Hi, obviously I am a long time lurker. I signed up to ask a question about my March 2005 trip and have been reading ever since. Always felt I was a bit too young to chime in (I'm 20) but have always been so interested in the conversations.
However I couldn't pass up replying to this topic. I have never lived in South Dakota but my Dad is from Rapid City and I have been there for at least a few weeks every year of my life.
Rapid City is a beautiful place to live with a great atmosphere and amazing natural beauty and tourist attractions. To start with it is only about 20 mins away from Mount Rushmore which is right outside Keystone, SD. You must stop there and get some taffy from the taffy shop, you can also watch it being made right on location.
Rapid City has a great free park for kids called Storybook Island which features Disney Characters (a walk through Snow White House, Cinderella's tower, etc) There is also a Dinosaur Park.
If you like hiking Harney Peak is close by which is the tallest mountain east of the Rockies, takes about a 2 hr climb. It is also really fun to go tubing on the creek that winds around the town. About an hour's drive away there are some fantasic caves to tour.
One of our favorite things to do is to drive out to Custer where the Black Hills Playhouse is located. We have seen many great shows there including the Sound of Music, Brigadoon, and Nunsense. There is also a wildlife loop to drive around there where you can see buffalo, tons of prarie dogs, and other animals native to South Dakota.
The shopping is also decent (although I am from outside Philly with plenty of shopping) I still have fun at the Rushmore Mall. There are many restaurants to try in town. We love Casa Del Ray which has great mexican food.
Overall, Rapid City is a great place to live and visit with friendly people and way more to do then any part of South Dakota I have ever been and I have been plenty of places (Sioux Falls, Brookings, Mitchell, Huron) The only negative thing is that it can get really hot in the summer and FREEZING cold in the winter.
I think you'll like it. If you have any questions feel free to PM me and I will either help you or ask some family members that still live there. Good luck!
I was going to bump this up as we need to drive back to Iowa to pick up some inherited items this Spring and I have never been thru South Dakota going to the midwest! I am hoping to pick up some travel and tourist tips down the road.... 
So.....keep in touch once you get moved! 
