They look very cool but you are right as they are so easy to make yourself. Another simple modern solution for unique magnets is with the glass pebbles you can get at craft stores. Put letters underneath, textile or some funky design with wallpaper, then after modge podge-ing it, just add a magnet. Voila! Here is an example:
http://marayagalleries.blogspot.com/2007/04/glass-pebble-magnets.html

Or you can paint all the free magnets you get with some strongly adhering paint and you have all sorts of shapes but all coordinated.

I have little super-powerful coffee beans. I love them.

I've turned some of my rocks into magnets. I like using gemstones though, currently I have up goldstones, tiger's eye, jasper, amethyst, and a couple quartz varieties.

I wonder if one can have too many rocks? I've always been drawn to them and pick them up when I go places. On my To Do list is make knobs for my cabinets with some of my treasures, and I fell like I should thump myself in the head for not thinking of this - they're great!

A proud Mom...just wanted to brag a bit...these ROXX magnets were designed by my son Shaw Quan.
At the time they came out he was 8 years old (he originally made them with rocks found on the East Coast of Canada)...he is now 11 and they have been a top seller for Umbra for about 3 years!