Tumblr. I remember first posts around my online social circle mentioning this easy, simple blogging platform, and lots of people including me started using it r

Tumblr. I remember first posts around my online social circle mentioning this easy, simple blogging platform, and lots of people including me started using it right away. I'm still a big fan and use it in lots of different ways. Posterous. Here the first thoughts were different and it didn't kick in among most of my friends. I used it for some time as an experiment and got to know it quite well, but somehow I didn't enjoy it too much, now I know I'll be using this platform for some projects soon. Flickr. I wasn't much into photography back then, but my mates who were active photogs got crazy about it. At first I really didn't like it, partly because of the early UI/UX, partly because I wasn't really sure about the idea of hosting pics 'out there' and didn't like the ToS. After a few years, when I got into photography as a hobby, started using it right away (exploring and sharing) and I do it actively to this day. Youtube. Lots of local companies, which are probably irrelevant to most of the HN crowd, but I'll mention some anyway: gadu-gadu (from a simple sms gate app to being THE instant messenger in Poland completely killing ICQ here), grono.net (first leading social network), nasza-klasa (classmates social network), wykop.pl (digg clone).