I went ahead and threw the Ace Fingerless Mitts on the Free Pattern Testers group over at Ravelry. For the uninitiated, Ravelry is a website sort of like Facebook for knitters (only much more useful and less voyeuristic), and the FPT is a group that has a nice simple framework where you can get a new pattern tested, and/or to help designers out by working through their patterns.
I've been on both ends of the system and had mostly good experiences. I love to test for people--you get first crack at new designs with direct access to their creator, and it's fun to go through a bit of the design process with someone else. Of course whenever you put something out for 'everyone' to see, there's the potential for the devastating specter of non-constructive criticism (whether real or imagined) to rise up and bitch slap you in the face. I like to think that I've developed a reasonably thick skin over the years, and for the most part I think I have.
At work discussing science-y stuff, I will shoot you down and convince you to believe whatever inane bullshit happens to be spewing out of my mouth that day--I'm not really sure why it's different for designing something to knit. Maybe it's because fashion is so subjective, almost art. If someone says you're wrong, you can bust out mad logic skills, but if someone says your work is ugly--game over, man. No on wants to be told they're uninspired (or end up on Regretsy).