I feel people were a bit unfair with you here. I was in a similar situation to you and was able to find an excellent fit for my needs.
The bag is called the
Tenba Messenger Bag (Large). It comes in a variety of colour options and is more than capable of holding a dslr, plus lenses as well as a 15" laptop. When I received this bag I was thoroughly surprised at the quality of this bag. The shoulder strap has a very large padded cushion which will definately help in times when you are carrying a heavy load. Additionally, this bag has what seems like an unlimited number of pockets everywhere, including a quick access pocket on the top for your dslr.
The best part is that it sells for $101.93 on Amazon.com and includes free shipping. Link here:
http://www.amazon.com/Tenba-638-231...1_fkmr1_2?ie=UTF8&qid=1272914394&sr=8-2-fkmr1
I relied on some pictures and videos for this bag which I will link you to as well.
Pics:
http://photography-on-the.net/forum/showthread.php?t=694314&Tenba+Messenger
Video:
http://www.youtube.com/watch?v=qIj-iPAuEd8
Best of luck.