I have not hitchhiked around Iceland before, but I have picked up dozens of hitchhikers in Iceland. There are 458km between Höfn í Hornafirði and Reykjavík. I would not count on being able to hitchhike all that distance in one day. Very few cars will be going the whole distance in one go, so you would probably need multiple rides. Much of the traffic will be travel related and they are probably going to stop over in Vík, Kirkjubæjarklaustur or Skaftafell.
However if you start at Höfn and aim for Reykjavík i recon you would have greater luck. It’s still a stretch, but finding people, locals or tourists in Höfn going to Reykjavík should be a lot easier than the other way around.
I posted a while back about hitchhiking and other ways of travel in Iceland.
Thanks for noticing. I’ve been offline most of the time over the past couple of months, climbing, skydiving and guiding.
I don’t frequent them much, but Smekkleysa (Bad Taste) is a classic. Smekkleysa is both a record label and a store on Laugavegur, downtown Reykjavík. They were founded around the Sugarcubes and have stayed involved with Björk ever since as well as taking part in the early days of Sigur Rós.
There are some more stores, which are newer and come and go. However you will all find them in the same area of downtown Reykjavík.