In the same line as those sites that have you draw a pig or some other piece of work online, Make-a-Flake allows you to make your own virtual snowflakes. I tried playing around with it this morning, but didn't do so well. I'm not exactly sure how to work the scissors (no, I didn't read the directions carefully).
But at the very least, it reminded me how to fold paper to physically cut out my own snowflakes. That's a project I've been trying to figure out for the past 8 years or so (not trying very hard, but still....).
Update: I just did figure out how to use the scissors. You really need to make a minimum of three snips: a start at an edge, a point somewhere inside the flake, and then back to the edge. The tool isn't necessarily optimal, but it can be done.