As it turns out, modern day Reykjavik is no longer the quaint, fish market-filled old port city of yesteryear. Apparently the cat's been out of the bag for a while now. However, if you're interested in getting a feel for life and customs on a local level, make your way over to the weekend Kolaportið Flea Market not far from Reykjavik harbor. Don't worry, it's indoors. Here, amid the stalls and strings of hanging lights, you'll find bric-a-brac aplenty including books, Nordic (and non-Nordic) clothing, footwear, instruments, Icelandic (and non-Icelandic) records, games, pictures, the works; everything new and used, and everything fantastically displayed in a way that couldn't be further from a 21st century shopping mall.
If you're of a more gastronomically curious disposition, Kolaportið's got you covered there too. In fact, this is one of the few easily-accessible places left in the city where you can pick up traditional delicacies like fermented shark meat, dried fish and spiced horse sausage. Don't be too apprehensive, though, as there's plenty of less-exotic food to be had as well. Just be sure to bring enough cash (credit cards are becoming more widely accepted these days, but better safe than sorry) and enjoy the kitschy, oddly-flavored side of Icelandic living.