Oh, you've got some fun equipment. All I have is my D50 and 18-200mm Nikkor VR. I can't even afford a flash unit hahah! I guess that just comes with being a student who can't get a job. But, I make do with just the camera/lens! Natural lighting is my friend.
I'm getting there. You use what you have, and use it well,that's what makes a great photographer, not having the best of the best. I'm currently salivating over the new D700's, but until I get that kind of income, my little D5000 serves me well. Natural light is great, lol and it's free and you don't have to plug it in or pop in the AA's.

Your gear builds slowly as your knowledge base and skill does. I have some good gear now but I maxed that D80 out. Still have it too! Your next lens purchase should be a 50mm. Mmm! My yummiest and most used lens- excellent and fast in lowlight.