Stumbleupon and Digg, anyone familiar with them?

[BTM]

Anyone use these programs?  What I understand, StumbleUpon is a program to find new websites based on your interest, and Digg is a good way to get people to come to whatever website you're promoting (or you blog posts).  I was curious if anyone's tried thing.  Only thing that was me concerned about say, StumbleUpon is exactly what information they're collecting about your visiting habits... while having getting info on brand news sites that would be of interest of me would be cool, not sure I'd want a database of all the places I surf to floating around.

Granted, there's probably already several of them anyway, but still...

[Captain Tars Tarkas]

Someone submits one of my pages to stumbleupon every few months, they always mess it up somehow and submit either a random navigation page or have the address error out to a blank page.  I've never used them myself as I have enough things wasting my time on the internet, I don't need more!

[Derf]

I use Stumbleupon occasionally, though I just look at the links; I've never officially joined the site. It's an interesting concept, and it seems to be done well, but I guess that doesn't really answer your question about how it uses personal info since I don't give them any.

[Ash]

I've visited Stumbleupon a few times and have checked out some links.  Despite all the stuff there, I haven't found any memorable websites through it yet.

Never really did know what Digg was.  I went to that site awhile ago and remember that their descriptions and FAQ's were kind of vague.  Still don't actually know what Digg is and/or does.  

[Andrew]

I've used both.  Digg seems to be good at catching the "what's hot right now" topics, and sometimes bringing to light interesting things that might otherwise stay below the radar.  It works on something of a vote system. The more people who Digg a page, the higher up on the Digg headlines it goes, meaning more people see it.

StumbleUpon seems more long term.  People discover worthwhile pages, add them to StumbleUpon, and tag them.  If you are "stumblin" and pick a movies tag, it will randomly deliver you to a page tagged as such.

I have not looked carefully into if either monitors your habits.  However, I have not seen StumbleUpon try to report back through my firewall when I did not have the toolbar open and using it.