I guess everyone's seen this already (popular because it runs on Android) but there's another PSP emulator for OS X:

www.ppsspp.org/

PPSS (har har): you need to build it from source right now.

I believe that it runs very few games (some Bubble Bobble/Snood hybrid might be one of the only ones), but with the number of code commits a day they're getting, this will be a great emulator before long.

I was going to be negative about this, like with the Java PSP emulator, but I see it's by a co-author of Dolphin, whose impressive development history gives me hope.

Of course, I still prefer my PSP-2000, custom firmware, and always connected via Component video-out (I bought a HDMI PSP adapter that supposedly was able to make it output fullscreen rather than the 75% fullscreen annoyance, but it blew an HDMI port on my A/V receiver and I put it in a corner and just used official cable...).

But an emulator may be useful for hackers/translators - which is super important to me as I am patiently awaiting the Valkyria Chronicles 3 fan-translation that I hope will be a Christmas present to the Internet soon...