After scouring the web (including 1src) for this baby, and what few references/links I did find were all dead, I have found and posted this very useful little Wi-Fi application here: Clie Netmon
To my knowledge, it works on Sony Clie NR, NX, UX, and TH series PDAs. Not sure if it will work on Palms, etc. Use at your own risk (although I think it will either work or it won't, without doing any damage).
Here's one of a number of threads about this app: Clie Netmon Thread
For more, search: netmon