I pulled the trigger on a couple of lenses - The DA* 55mm for portraits and household usage ($450 used from Adorama in perfect shape), and the 100mm Macro for macro/plants type stuff ($360 from BHPhoto brand new).
I haven't used the 55mm much, but I took the 100mm into town and paraded around the house with it while it was raining. I LOVE this lens. It is crystal clear and has amazing colors. A little tricky to shoot with at first, but I'm starting to get it down.
I think I'll end up purchasing a Pentax 15mm or 21mm for landscapes pretty soon, as I found myself using the 18-135mm for all my wide shots. The 18-135mm is still a great lens for when I'm wandering around, but when I want to set up a large shot, I think id want something more dedicated.
Here are some examples of what I got with the 100mm and including a few of the wider shots I took with the 18-135mm.