How long do want the paint to stick for????

1. Take it to a powder coater. Under $200 gets you frame and fork, zinc rich base coat, color coat and clear coat. Only downside is that you only get one color and you must tape the bb thread yourself. Also the paint is not very resistant to chemical attack, ie. poly paint thinners will strip it off.

2. Buy yourself a cheap sandblaster at the auto refinishing shop - I paid about $30 for mine. I use fine, hand selcted, world class, premium quality BEACH SAND from the local beach - plenty to choose from - about 2000km of it. Tools required - shovel and bucket. Note: for frustrated coal miners who like to get REALLY dirty, get a bucket full of ilmenite - it works much better than sand.
Find a big open space, put on your daggiest clothes, and a cheap pair of safety glasses, and go for it. This gets off all the paint and any underlying rust.
Prime with a light coat of etch primer - from a can, then with a 2 pack primer/surfacer. Alternatively, one or two coats of EtchPro (Epoxy etch primer) from a can.
Sand with LOTS of water to your desired finish - I go to 1200 grit, but don't start any coarser than 500 or you'll have to spray it again.
Spray the finish to suit yourself. I use one coat of base color, masking for multi colors, then a single top coat of clear polyurethane - MS clear is fine for a bicycle frame (and cars). The base coats dry in 5 minutes, the clear top coat dries in 10 minutes and cures in about 3 days.
This finish is almost indestructible, physically and chemically - stones bounce off it, paint thinners just make it cleaner. Polyurethane is much better than epoxy for impact resistance. The only downside is that if you breath the vapours when spraying it WILL kill you - so don't!!! (this really only applies to the clear top coat).

This is also how I paint radio controlled jets - and they have kerosene on them all the time - never damages the paint.

Hope this helps,
cheers