What are some unusual things to see and do in Reykjavik area?

If you liked the hakarl (putrified shark) you ate in Reykjavik and want to learn how it's made, you can visit the Bjarnarhöfn Shark Museum (link to their facebook page above), which is about a 3 hour drive from Reykjavik in a beautiful area on the Snæfellsnes.  My Icelandic best friend and I went there about a year and a half ago and it was a riot!  We were the only ones there that day, so we got to see areas that most groups don't get to see.  We got to watch a dead shark being dragged from the beach to the processing area on a forklift, then we got to help hang the fillets in the curing shed.  We learned how hakarl is made and got to taste it fresh from the source, and it was a lot of fun.  The smell clings to your clothes and makes for a rather unpleasant drive back to Reykjavik, but it's well worth it!

Understandably, most people who visit Reykjavik and go to a thermal bath/pool, go to the Blue Lagoon spa, which, given its location, is otherworldly. However, if you want to get more of a sense of community and live like a local, try Laugardalslaug. It's in town (not far at all from downtown) and wonderful most any time of year. Regarding scenic tours, a lot of people do the Golden Circle. I think there are some areas a bit further away that are really incredible. If it's not on your list, I'd definitely recommend some glacier hiking (like Skaftafell National Park to the east, for which the drive alone makes it worthwhile).

My favourite part of the trip to Iceland was the Vik area, we did an ATV tour of the black sand beaches that was amazing -- we were the only ones there.

I think Heimaeyand the Westman Islands Gamli velasalurinn Vestmannaeyjum were my favorite part of visiting Iceland. We took the ferry over and stayed two nights there. Slippurinn Hárgreiðslustofa was an incredible restaurant experience and the Volcano Museum (since part of Heimaey didn't exist until 1973) was wonderful. We also played golf and hiked!