ear plugs and swim caps

I used to shorten the stem. Now I use custom earplugs.

Best ear plugs ever invented...

http://www.proplugs.com

They are flush with your ear so you can wear a cap over them easily. They're comfortable, never ever fall out, and do their job well. Initial purchase price is a bit high relative to other ear plugs (wax etc), but you only need one pair, they last forever. You do need to make sure and order the proper size, but they have a sizing kit and instructions on fit so this is pretty easy.

I've been using the same pair now for two years, in open water races and lots of pool swims. Never had one fall out, never had any problems.

Mike