I've spent a lot of time recently with the Stumble application and can now recommend it to anyone who is curious and has the time to indulge in random websurfing. I have had just one problem: If I am on Stumble for any length of time in Windows Explorer 8 there will be a hangup and while Stumble still works, getting the browser to close, at least on my PC, requires a three-fingered salute. So there is possibly a bug in there somewhere.
Another important note: Stumble does not normally call up websites that have nudity or pornography. You can set your filters to allow these images if you want, but I am not sure that such selection is reversible. Stumbles filters give you a wide range of topics to select so that you get mostly websites that may have something of interest to you.
Using Stumble has led me to some amazing photographs, especially from the various space agencies that post pictures from Hubble and the other space telescopes. Also, I have found a great many historical photographs, inspiring photographs of Earth's many landscapes and animals, and more thought provoking websites than I ever imagined. There is a feature that allows you to share your stumblings with most social networks, too.
With anything you get from the web, you'll need to cross check for credibility and make sure you have an antivirus/spybot working for safety as some bad things can and do get through even the most protected sites.
You can get the Stumbleupon toolbar here: http://www.stumbleupon.com/download.php
