A couple of fun links for you!
The Safety Sign Generator will construct an OSHA-approved warning sign of your design, with proper graphics and your choice of colors and text! Let your inner Bart Simpson have some fun. I made a bunch of these a while back but can't find them. When I rediscover 'em, I'll post 'em.
And, via Wil Wheaton Dot Net, comes the button maker from Kalsey Consulting Group. Make your own little "stickers" for your blog or website. Go to WWDN for examples.