http://diynet.com/diy/bo_enhancement...278297,00.html
diynet.com has a couple articles on the topic. This show really kicks, when I get a chance to watch it. Anyway one rticle above is on applying ablative paint and there is another on coating a new hull. There's also one on applying an epoxy barrier coat, which sounds like a nightmare worth of work.
If you haven't seen the website I suggest you add it to your favorites.
My bottom paint is starting to chip off my trim tabs, but seems to be ok just about everywhere else. I typically haul my boat after every use. It stays in the water overnight probably 6 or 8 weekends out of the year and perhaps a week stright on 1 or 2 occasions. I'm goinf to scrap as much loost stuff off the tabs and respray them. I think I can get at least 1 more year out of the bottom paint.