...easily, with a 'bump key.' This tells how to make a key that will fit almost ANY lock. This is scary.
http://www.youtube.com/watch?v=pwTVBWCijEQ
There are several "how to" video's there.. It looks too easy.
web-search "bump key"....
Way too complicated. The best universal key is a auto body sliding hammer with a stainless steel screw on the end....thread it into the brass lock and just a few hits will pop out nearly any lock cylinder.
)I can get in your front door....

Something to think about....if I was driving by a house where a guy had his key ring out and unlocking his front door I wouldn't think anything about it...but if he's banging on a screw driver in the key hole, or kicking it with what ever size or type of shoe he may be wearing I may think about that one and call the cops or something.