What I would like to see from StumbleUpon now is an easy way for people to use the service no matter which browser they are using. I would think that they could come up with a Bookmarklet or something along those lines so that people can shuffle through some sites when they are looking to kill some time.

I find the other social sites like Digg and Reddit cold and unfriendly, with many users just jumping on the latest hot topic or keen to see how many diggs a particular post can get, there doesn’t seem to be much social element to those sites. I find it really difficult to connect with users on those sites. I’ve seen a lot of quality content on those sites get buried.

I find StumbleUpon so much more friendly (as you mention in your post), with a lot of really good quality content. I’ve built up a good user base of friends and I like the ‘network’ page which shows who has visited my pages, it allows me to easily connect with fellow stumblers who share similar interests. I’ve found a lot of good sites that way.