This last summer I did a couple of sprint triathlons. Fun and addicting AND it gives me something to work towards, some motivation to exercise. I also appreciate doing multiple sports, which is great for someone like me who has exercise ADD.
Here's a bunch of swim workouts I've done and am still working through. Err...was working through. I'm on a bit of a hiatus as of late.
Some of these are gathered from sources around the web, quite a few of the main sets came from Scott.
CLICK HERE for a pdf of the workouts.