Re: tri on a beach cruiser?
I say go for it!! No one is going to laugh at you. I might laugh, but only because I think it's cool, not because I'm making fun of you.

I think everyone would just be thinking, "Cool, they are out here doing a triathlon, even without a fancy bike!" Come do a tri in Austin, and you'll fit right in. Our motto is "Keep Austin Weird" If you ever walk down Congress or 6th street, you would definitely know why!!

Yeah, just make sure you don't have any safety violations, and make sure your bike is in good working order. You'll catch the bug, then you'll be at the bike shop the next day looking for a new road bike! You might catch the bug before you ever even do your first race, though. That's what happened to me! I bought my road bike 2 weeks before my first race and signed up for 2 more sprints before I ever even did my first race.
Kelli