I recently made a trip back to the country of my birth, the Philippines, for a wedding. While I was there I was told there were a lot of places to get a PSP downgraded, so I thought I'd explain the process since someone might find it interesting.
Wages in the Philippines can be very low; the minimum wage is around 5 or 6 dollars a day. Downgrading a PSP can be done in major shopping malls in Manila. Young men will solicit passers by at a sort of booth among others that sell electronics. They charge 300 pesos or so, which translates to less than 8 American dollars, so the people that do this can make a relatively decent amount of money for a fairly simple process. For comparison's sake, a cleaning at the dentist without any insurance costs about 400 pesos, and I saw signs offering haircuts for 50 pesos.
Piracy is widespread in the Philippines, so it's basically assumed that if you get a PSP, your going to pirate games. Imagine buying a new PSP game even at double the minimum wage. That could be a full weeks worth of wages just to buy God of War, so it's no surprise that people there have no qualms taking the piracy route instead of paying half a months rent to get a video game.
So at the downgrading center, which consists of basically a guy sitting at a computer and the aforementioned solicitor, there's a 3-4 page list filled with the titles of games and the file size of the game. I saw what looked like all of the releases that have come out in the U.S., and seemingly not European and Japanese releases. I asked if they had Echochrome and they seemed to have never heard of it. Installing an emulator also seemed to be possible; they said they had a GBA emulator, but when I mentioned Neo Geo they didn't know what I was talking about, so it seems if you want to put less known emulators or a homebrew app, you're on your own. Installing games costs about a $1.50 a pop, provided you have a memory card, which the attached booth was selling for the prices that were about the same as you'd find in the states. There was only one choice of firmware, though it was the latest version of a very common CFW, and they install a game free with the downgrade.
The process takes about 5-10 minutes, most of the time just transferring whatever game has been chosen to the PSP. When they're finished, they boot up the PSP in front of you and show you your firmware version in the XMB.