I came across a discount code for the Hunger Game e-book trilogy that is an AWESOME deal! It's from kobobooks.com and expires March 31, 2012. Although, sometimes these codes go out of control on the internet, so if you're going to by them, do it soon!
The codes are HungerGamesDeal2 for Hunger Games (ends up being 83 cents), HungerGamesDeal3 for Catching Fire ($1.16), and HungerGamesDeal for Mockingjay ($1.07). So you get all 3 for like $3!
I guess Kobo has their own e-reader, so it's not a file that will just automatically play on everything. It is an EPUB file, so if you check out books for a Nook, it will download to Adobe Digital Editions like the library books do. If you're trying to read them on a Kindle or iphone, check out Kobo and see what they say. You may have to download some sort of app or conversion.
I did buy these and they downloaded nicely to my Adobe Digital Editions, which I'll just transfer over like I do library books.