Sony has started to offer PSone games as downloads on its PS3 Store, although you can only play them on the PSP at the moment.
It makes sense somehow - basically, American gamers can log on, pay US$ 5.99 and download one of the five initial offerings, and then transfer it to a Memory Stick Duo using a USB cable to play it on the handheld, which needs to be plugged in prior to starting the download.
The first five games offered are Crash Bandicoot, Cool Boarders, Syphon Filter, Hot Shots Golf 2 and Namco's Tekken 2.
There are some limitations though. For a start, you'll need a Memory Stick with enough space on it to hold the game in question - with 157MB (Hot Shots Golf 2) being the smallest - and on top of that you're only allowed to transfer the game onto five different PSPs before you're locked out.
Whether that means you can only transfer it to the same PSP five times is unclear from initial reports, and although we have a retail PS3, we don't have an American credit card so we can't actually do the business ourselves. Hrrmpf.
Furthermore, it's worth noting that each of the games comes with a disclaimer noting that multiplayer functions are disabled, because Sony has not updated the games to work using the PSP's wireless networking element.
Sony has previously said that it aims to allow for emulated games to run on PS3 sometime soon. You can already use the PS3 to play most PSone and PS2 originals if you have the discs.