Dual Booting the iPaq?

dualBootless asks: "I just got an iPaq 3670 on eBay, and I plan to try out the Sierra Wireless Aircard 555 PC-card with it (I am fortunate enough to live in an area supported by Verizon's 144kbit G3 service). Unfortunately, there is not yet Linux support for the 555, so I'll be stuck with WinCE. I would like to play around with Linux too, but re-flashing the rom every few days seems out of the question. Has anyone been able to dual-boot WinCE/Linux on these hand-helds? I'd be willing to put Linux on a compactflash if necessary, and swap the PC-card expansion pack for the compactflash one whenever I want to use Linux."