Huff. RNG. Can't be assed.
http://gts.kanojo.de/
Go down and click on "Your Storage" to set up an account. From there, you can start saving the Pokemon they put up for download, as well as uploading your own. It works with both Gen IV and Gen V games. Once you've uploaded or saved a Pokemon to your online storage, you can edit it. You can change its move sets, IVs (though not with Pokemon you've caught in the wild), EVs, EXP, held items, nicknames, Pokerus status, and contest values. You cannot change certain things, though. You can't change a Pokemon's nature, or whether it's shiny or not, or its individual stats. (Yes, that means you can't have a Pokemon with impossible maxed out stats.)
They put up a new Pokemon every day to give away for Gen IV and Gen V. So far, most of the Pokemon in the Gen V giveaways have been from Gen IV or earlier, but there have been some shiny Unova Pokemon too, like Litwick, Zorua, and currently Roggenrola. The majority of the Pokemon they post are shiny, no matter what region they're from. Any Pokemon in the Gen IV giveaways can be transferred to Gen V but they can't be transferred backwards.
You can store your own legit Pokemon on the site and delete them from your boxes to free up space. It's a really handy way to check IVs and EVs, too.
It's a handy tool, no matter what you do with it. I think it has a few problems in Chrome, though....