Question
What is a "Signature" Visa?
Why do I want one?
How do I get one?
How much does it cost?
Is it worth it?
Which one is the best one?
Any experts out there?
Answer
See http://www.usa.visa.com/personal/cards/credit/visa_signature.html?it=c|/personal/cards/index%2Ehtml|Visa%20Signature
Since you're a partial UA flyer, you may be interested in
http://www.flyertalk.com/forum/showthread.php?t=465353
http://www.flyertalk.com/forum/showthread.php?t=113771
http://www.firstusa.com/cgi-bin/webcgi/webserve.cgi?partner_dir_name=united_signature_20k&page=cont&mkid=6VBD