Bounce flash and off camera flash is the ticket for sure
I found a $25 alternative to the SB-400 called Sunpak Quantaray QF30, it's a similar shape and power. It doesn't recycle fast enough for weddings ect, but it's fine for the home shooter. I use it on a Nikon D3100, it's TTL. I bet they make a Pentax version too.
For about the same price, I've had good luck with Sunpak 933. It's fully manual and can bounce and rotate completely. It's like a cheaper alternative to the Yongnuo YN40. The only difference is, the latter has adjustable power.
An awesome video that shows how to do off camera flash is called OneLight by Zach Arias. I found it via torrent.
David Hobby's 2nd video is a good follow up to that course, it's called Lighting in Layers.
Here Ken Rockwell shows how you can use direct TTL flash to fix shadows in high contrast daylight scenes :
Fill Flash
Cheers,
Craig from Maine