HP-48GX and HP-48SX (tested with C860 and Nokia 770, reformatted for 640x480 screens):
http://sense.net/zc/x48HP-42S (tested with C860 and Nokia 770, new 640x480 skins added with Zaurus keyboard hints):
http://sense.net/zc/free42HP-35, HP-45, HP-55, HP-80, HP-21, HP-25, HP-32E, HP-33C, HP-34C, HP-37E, HP-38C, HP-38E, HP-41CV, HP-41CX, HP-11C, HP-12C, HP-15C, and 16C (tested with C860, some 640x480 friendly skins added for 35, 41CV, and 41CX. 11C-16C already 640x480 friendly):
http://sense.net/zc/nonpareilEach site has screen shots, downloads, links for more information and source, patches, benchmarks and results.
I am switching to pdaXrom (when I can find a free weekend) and will have different URLs for pdaXrom binaries if the above binaries do not work with pdaXrom.