Last week, I mentioned the HomebrewPSP Converter from the same people that make iPSP, and commented on how I thought they would soon have an update that would allow users of PSPs running v1.5 firmware to run homebrew apps and emulators without having to swap memory sticks.
Well, my prediction was right. Get it now. It even has the option to automatically put the converted game on a PSP that you've mounted on your Mac. Very nice.