The linux-mips site has some info
http://www.linux-mips.org/wiki/Systems.
Sadly, it looks like MIPS support has fallen behind some of the other handheld platforms. What information I've found so far is woefully out of date and full of dead links - activity seems to have died off around the turn of the century.
I suppose what's really needed is a "JLime for MIPS" project to kickstart things again.