Possible to run 2 different brands of ram in ddr?

I have 2x256 Simpletech PC2700 and a 1x512 Infineon PC2700 ram. It's running DDR at my specified timings of 3-3-3-11 @ 182 FSB. Is this common?

I didn't know you'd be able to run DDR with 2 different brands.

All DDR can be mixed and matched... Different ram can't necessarily be run in Dual Channel however.