This website helps you see if an online pharmacy is legitimate or not. It's the only one approved by the national pharmacy boards association. You can also report spam and fake online pharmacies. One big point in its favor: since it is approved by the pharmacy boards, it has some accountability built into the process.
I do a little spam reporting and there's a big problem with websites like sitejabber.com being infiltrated with the owners of shady sites (like the illegal online pharmacies) submitting negative reviews on their "enemies" like spam haus, legitscript, and others. But Legitscript is definitely legitimate and very helpful if you need to know if a Internet pharmacy is on the up and up.