Iceland is great! I was there last Sept. and really enjoyed it! 7 of us rented a van and drove to the Blue Lagoon to soak, spent an hour or so there (I could have stayed longer, it was great)! From there we drove to the Falls and the Geyser, well worth seeing.
Trouble we found with the tours is you couldn't do it all. We wanted to swim in the Blue Lagoon as well as see the Falls and Geyser, none of the ships tours allowed enough time to do everything plus they included a lunch, too, which takes up time.
Hope you find others to share your tour. We met up on Roll Call Boards ahead of time.