ok, so here's the deal. i am going to start off with as much info as i can get on the accu-rite line. what i am attempting to do here is give a brief intro or description of what case each model is best for. then i will post a link for more info and a pic. the reason i am doing this is to make it easier to find what we are looking for and cut down on questions that have been answered over and over again. by all means if you know there is something not covered or there is something you use and are a fan of please add it to the list. the reason i am starting with the accu-rite line is they are proven and inexpensive, with the added bonus of not spending all your supply money making another pet store owner rich.
i also want to add that these may very well not be the best prices, just where i find the info... so look around.
here they are:
1)
Acu Rite 00592W Wireless Indoor Outdoor Thermo-Hygrometer & Moon Phase Atomic Clock

this is best for temp and humidity in several vivs... all tropicals if you wish! up to 4 if you purchase 2 extra remote sensors. the main unit will do 32°F to 122°F (0°C to 50°C) and 20%-99% RH. each remote sensor (up to 3) will do -4°F to +158 °F (-20°C to 70°C) and 20%-99% RH. it also has a couple of other features like an atomic alarm clock that may forget to set itself if it rains or is real cloudy, but who cares... you can read the temp and humidity in 4 vivs at one time with highs and lows for each that reset every 24hrs. Sale price: $29.95, 2/$59.00
2)
Acu-Rite 00590A1 Wireless Indoor Outdoor Thermometer, Indoor Hygrometer and Self Setting Clock

this is best for temp and humidity in one viv, and temp in up to 3 more. or hot and cold temps in two, one of which can have humidity also. the main unit will do 32°F to 122°F (0°C to 50°C) and humidity (unspecified). each remote unit (comes with 1 also... can handle up to 3 also) will do -4°F to +158 °F (-20°C to 70°C) with Alkaline batteries, or -22°F to +158 °F (-30°C to 70°C) with Lithium batteries. Sale price: $16.95, 2/$33.00
3)
Acu-Rite 00604 Digital Wireless Indoor/Outdoor Thermometer and Alarm Clock

this is best for 2 temp zones or temps in 2 vivs. the main unit does +32°F to +122°F (0°C to +50°C). the remote unit will do -4°F to +122°F (-20°C to +50°C). Sale price: $14.95
4)
Acu-Rite 00611 Wireless Indoor/Outdoor Thermo-Hygrometer

this is best for temp and humidity in 2 zones or 2 vivs. this unit also records temperature highs and lows for the remote unit. the main unit does +32°F to +122°F (0°C to +50°C) and 0% to 99% RH. the remote unit will do 40°F to +158°F (-40°C to +70°C) and 20% to 99% RH. Sale price: $22.95, 2/$45.00, 5/$110.00
5)
Acu-Rite 00612 Wireless Indoor Outdoor Thermometer

this is best for 2 temp zones or temp in 2 vivs. this unit also records highs and lows. the main unit does +32°F to +122°F (0°C to +50°C). the remote unit will do -40°F to +158°F (-40°C to +70°C) . Sale price: $22.95, 2/$45.00, 5/$110.00
6)
Acu-Rite 00754 Wireless Weather Station

this is best if you have the need to measure temps in 2 zones or vivs or in a variety of areas with added remote sensors. the remote sensor that comes with it does not have a probe, but any that are bought separately will each have one that is water proof and detachable. this means you can measure your basking area, cool side, soil and pond temps... or whatever you can think that may apply. the main unit does 32° to 122°F (0° to 50°C). the remote unit does -58° to +158°F (-50° to +70°C) (with probe). Sale price: $28.95, 2/$57.00
7)
Acu-Rite 00782 Indoor/Outdoor Wireless Thermometer

this is best to measure temps in 2 zones/vivs. main unit does 32°F to 122°F. remote unit does 0°F to +130°F. Sale price: $15.95, 2/$30.00, 5/$72.50, 10/$140.00
8)
Acu-Rite 00786 Wireless Digital Thermometer

this is best to measure temp and humidity in one area and temp in 1 (up to 3 with extra remote sensors) other area(s). the remotes may even display rh on their own... not sure from the description. the main unit does +32°F to +122°F (0°C to +50°C) and humidity (unspecified). the remote unit does -4°F to +122°F (-20°C to +50°C). Sale price: $28.95
9)
Acu-Rite 00891 Digital Thermometer with Humidity Gauge and Clock

this unit is best cause froggy says so... lol. seriously it's best for temp and humidity at the main unit and another temp zone. the main unit also has a waterproof probe on a 10' cord. it also stores min/max temps. thanks to the probe the main and remote units can both do -58° to 158°F (-50° to +70°C). Sale price: $15.95, 2/$31.00, 5/$75.00, 10/$145.00
10)
Acu-Rite 00970

this is best for humidity and temp at the base and 1 (up to 3) more temp zone(s). the main unit will do 32°F to 122°F (0°C to 50°C). the remote unit will do -4°F to +158 °F (-20°C to 70°C) without the wireless probe, or -22°F to +158 °F (-30°C to 70°C) using the probe. Sale price: $22.95, 2/$45.00, 5/$110.00, 10/$210.00
11)
Acu Rite 00972

this is best for humidity and temp in up to 4 locations... even in the pond... and it looks sharp online... might not be too bad on your entertainment center for easy reference. the main unit does 32°F to 122°F (0°C to 50°C) and 20%-99% RH. the remote units do -4°F to +158 °F (-20°C to 70°C) without probe, or -22°F to +158 °F (-30°C to 70°C) using the waterproof detachable probe. Sale price: $33.95, 2/$66.00
12)
Acu-Rite 00973

this thing is packed with useful features for the office. this is best for humidity and temp in up to 4 locations... even in the pond... and it looks sharp online... might not be too bad on your office desk for easy reference. the main unit does 32°F to 122°F (0°C to 50°C) and 20%-99% RH. the remote units do -4°F to +158 °F (-20°C to 70°C) without probe, or -22°F to +158 °F (-30°C to 70°C) using the waterproof detachable probe. Sale price: $48.95, 2/$96.00
remotes below... hint; find the one you need by clicking on the link you chose your thermometer from:
1)
Acu-Rite 00739 Wireless Remote Temperature Sensor Sale price: $17.95, 2/$34.00
2)
Acu-Rite 00955 Wireless Remote Temperature Sensor Sale price: $15.95, 2/$31.00
3)
Acu-Rite 75321RS Wireless Remote Temperature Sensor Sale price: $18.95
4)
Acu-Rite 00911 Wireless Remote Temperature and Humidity Sensor Sale price: $16.95
NOTES:
1) NONE OF THESE COME WITH MORE THAN 1 REMOTE SENSOR... ANY EXTRAS WILL HAVE TO BE PURCHASED SEPARATELY (WHERE APPLICABLE [IT WILL SAY UP TO 3 REMOTES OR UP TO 4 ZONES IF APPLICABLE]).
2) IT IS RECOMMENDED NOT TO USE ANYTHING WITH AN LCD SCREEN OR ALKALINE BATTERY IN TEMPS UNDER -4 DEGREES FAHRENHEIT (-20 DEGREES CELSIUS)... IF REMOTE UNIT DOES NOT HAVE A SCREEN, IN MOST CASES LITHIUM ION BATTERIES OR A PROBE ARE SUGGESTED FOR LOWER TEMPS.
3) ALL OF THESE HAVE A LISTED MAXIMUM TRANSMISSION RANGE OF 100 FEET OR 30 METERS (WITH NO OBSTRUCTIONS)
4) MANY OF THESE MODELS HAVE CLOCKS. I AM SORRY I DID NOT LIST THAT FEATURE FOR MOST OF THEM. THOSE THAT UPDATE THEMSELVES MAY HAVE ISSUES IN BAD WEATHER (ESPECIALLY IF IT'S BAD AT NIGHT). BOTTOM LINE THOUGH FOR THOSE THAT MAY BE UPSET, IF YOU FEEL FOR SOME REASON YOUR GECKO OR FROG NEEDS TO KNOW WHAT TIME IT IS THEN FEEL FREE TO LOOK IT UP. THE LINKS ARE RIGHT HERE.
5) ALL SALE PRICES ARE FROM THE SAME SITE AND ONLY THERE FOR REFERENCE PURPOSES. THEY ARE PRICES AS OF 3/26/09 AND OF COURSE ARE SUBJECT TO CHANGE.