There's been a couple Particle systems posted. Orangy Tang posted one awhile back (can't find the link), and there's one that's been created and is available for public use at http:/www.j3d.org
Yeah, that was quite a while ago
Its on my website if you want to grab the code (link in profile, code in j3d). The one on j3d.org is more advanced last time i checked, but i got the nagging feeling it was slightly over-engineered.
Other than that, Gamasutra has a good article on particles that i used when writing it, and if you can get your hands on Max Payne then the particle fx editor should give you plenty of ideas (possibly the most flexible and comprehensive tool out there i've seen).