Sony has released a firmware update for PSP which... hang on, didn't we do this the other day? I'm certain we did. Yes, here we are. So what's this "3.01" update all about?
Aha! "Revisions to strengthen security". In other words, they've built higher electronic walls around the bits that might conceivably allow you to do something unsanctioned and naughty with your PSP (like installing an emulator, or buying a PSP from a man in Hong Kong perhaps).
So go ahead and install that if you want to help them out, although they'll just roll whatever they've done into the next update anyway if you don't. And if you missed out on the 3.00 update, there's an argument for grabbing this, since it will allow you to buy and download PS1 games and play them on your PSP. Er, providing you have a PS3.
For a more detailed list of recent changes, refer to PlayStation.com or head to Sony's Yourpsp.com website for Europe, which probably has been updated but we can't be bothered to check (it's a faff).