Everything But the Kitchen Sink

I'm been giving thought to what would be a set of reasonable requirements for a temperature sensor/datalogger. Here are some of my first thoughts in general order of importance:

• Very Low Power Consumption
• Best powered by a 3V lithium battery
• Active: < 1mA, Sleep: < 50µA
• Long Recording Period
• At least one week to several months
• Reasonable Recording Intervals
  • Event recorded every 15-60 minutes
• Rugged Construction
  
• Wide Operating Temperature Range
  
• Small Form Factor
  
• Easy Downloading of Data
  
• Inexpensive (<$50US)
  

That all should be easy, NOT! Considering I sometimes still put diodes and transistors into my protoboard backwards this could take awhile. It's a good goal though. This may sound a little sad, but this project has be more excited that any software project I've been involved with for the last few years.