If you happen to own a Sony Xperia S smartphone, you'll be happy to learn that the phone has received PlayStation Store suport. As of right now, you should be able to download the official PlayStation store app, as well as an application called PS Pocket.
But what sorts of games can you play on your shiny new Android smartphone? There are a variety of titles available, not the least of which include Rayman, Jumping Flash!, Destruction Derby, and WipEout, all available for somewhere around $6. As you might expect, you will have to create a Sony Entertainment Network account to download the games, if you don't have one already.
As cool as it is that you can get some classic games for a smartphone now, I don't really know how the Xperia S is really any better than any other smartphone. You're still looking at controlling these games with a touch screen only, and while I don't usually mind that, I think most 'hardcore' gamers don't care for it. If you really want a 'gaming' phone, have a look at the Xperia Play. It's got this radical new idea they are calling 'buttons.'