Using Chrome 5.0.342.9 beta on Ubuntu 10.04. Got a popup saying "The latest versions of Chrome, Firefox, or Safari are recommended for using pik."
Detecting the browser instead of the features is often bad practice: http://www.jibbering.com/faq/faq_notes/not_browser_detect.ht...
I'm whitelisting OS/Browser combos, and I haven't added linux yet.
According to jeresig, author of jQuery, one should not perform browser detection, instead you should use feature detection. Browser agent is not going to give you an accurate picture of what is supported because every browser likes to say they are mozilla/webkit/netscape/etc.