I've been testing a lot of websites that offer Trophycards. Some of them are automatic (such as PlayStation.com or Playfire), and support a lot of nice features.

However, I strongly recommend you http://ps3trophycard.com/. It also updates automatically, and it has the best characteristics of each of the websites I mentioned. It shows, the number of trophies you have, your last trophies, your country, your ranking, your PSN avatar...Additionally, it doesn't request your PSN password or e-mail, just your ID.

This is an example of my Trophycard. You can see that the background is from the game that your last trophy is from.