1) you can switch over to a sponge filter and get a device that allows you to control the airflow - I switched over to sponge filters for my divided tanks since I can run up to 4 sponges on one pump if I need to...
2) Depending on the filter type, you can do the bottle baffle that matt mentioned or you can stuff sponge/foam into the filter which is what I do.
I dont bother with the aqueon filter cartridges and stuffed the inside of the filter with foam made for Aquaclear filters and then stuck some foam where the water flows out of the filter. There is also a big, bushy silk plant right in front of the filter to break up the water movement even more. Sometimes I will squich a filter cartridge in there if I need to use carbon but generally its foam only. Plus with the foam, it will last alot longer then the filter floss or whatever it is they use to make cartridges out of - so cheaper in the long run if you dont toss it out every month (which in my opinion is also tossing out most of the bacteria you want as well. SOme people say no, but...to each their own.).
I do the same thing with the Tetra 10i filters as well, its a little different setup but it works the same way.
you want to use AQUARIUM sponge not something made for washing dishes.
Any brand of AQUARIUM foam/sponge will do. I usually use the aquaclear brand since its the most easily avalible.
I think now its under the FLUVIAL name