PSP Updates has posted the PLynx v0.2b which is an Atari Lynx Emulator for the PSP.
The current features listed are:
Atari Lynx emulation
Bad sound support :)
Save/Load emulator state
Change the PSP CPU/Bus clocks
In the future, PLynx will be making a number of changes including speed enhancements and increased sound support.
You can download PLynx v0.2b here
I myself was never a huge fan of the Lynx although I know it has some die-hard fans similar to the Game Gear. For all those who loved it though, I am sure you will enjoy this, especially once full support is released.