The other day I saw a can colander (like this: http://www.amazon.com/Progressive-International-GT-3966-Can-Colander/dp/B00004S7VI/ref=sr_1_1?ie=UTF8&qid=1344822907) in the canned vegetable section in the grocery store. My first thought was, "Huh, that could be handy," immediately followed by, "I could print that."
So, here it is.
This one (the 66mm file) is designed for a specialty food can, but the scad file is parametric, so you can adjust for the size of any.
If you have a request for specific sizes, I'd be happy to generate those and post them, just make sure to include the inner diameter of the can you want it to fit (I'll also add 1mm or so for a loose fit).
Unlike the commercial version linked above, this one is designed to fit into the can, allowing you to press the contents of the can using the colander if you wish.
This thing is a part of a collection of things featured in this post: http://www.protoparadigm.com/blog/2012/08/what-to-do-with-a-3d-printer-make-canning-jar-accessories/
You shouldn't need support material for the lip, but if you do it should only be on the outside and should be quite easy to peel away.
Make sure to use a food-safe plastic.