Solid state humidity sensors?

Here's a question for the electronic nerds out there. :)

I recently bought a nifty USB based multichannel A/D converter and am looking to build a portable weather station. Getting temperature, wind speed, etc. is all fairly straightforward (pending calibration!) but I know nothing about humidity sensors. Does anyone have exerience with these?

I could build a wet/dry termocouple/thermistor setup, but that would require a small reservoir of water; I'd prefer a no-maintenance system.


TY, John!

After looking about, I think I'm going to go forego using the A/D, and build a go-anywhere serial port version with one of these or similar sensors. They spit ASCII text straight into your PC. Slick!
Or hey, if you feel like spending about 5K, you can get yourself a Vaisala WXT510 Multi-Sensor. It's a neat little all-in-one, about the size of a 2-liter bottle that they are going to start using in early 2007 on the Oklahoma City Urban Micronet. I just wish they had a wedding registry...