Best one I found, and bought, was the PQI intelligent stick. Very very small (2 fit in a credit card holder.) and at a good price, I think I paid about £28 for 128Mb.
http://www.pqi1st.com/products/istick.asp
The USB 1.0 version does seem slow compared to a USB 2.0 stick a collegue had so i'd pay the extra for the USB 2.0 version of anything you buy.