To the OP, I've seen guys who can take better shots with a cell phone than guys with 10K worth of Leica gear. To take better pictures you need to tell a story and draw the viewer in. I found that when I first started shooting, I would fill up a memory card with 10 (at best) keepers. Now, instead of spraying and praying, I am shooting far less, but the keeper percentage has gone way up. Why? I am learning to compose better. Go to photo.net for inspiration and ideas. Amazing shots there. Go to kenrockwell.com for info on gear and technique. He's a bit of a nutcase, but the info there is solid and comprehensive.

As far as equipment goes, you already have everything you need to take great pictures. If you feel compelled to buy a lens anyway, I would simplify and go cheap. The 50 1.8 is dirt cheap ($100 new) and tack sharp. More importantly, a prime lens forces you to pay attention to composition by making you move around. With zooms we tend to get lazy by standing in one spot and composing by zooming.