Can gouramis be placed in a tank with a betta?

Both are anabantid, so both will share the surface level of your tank. There is a high chance your gourami will suffer from the betta. I'd say no to your question.

I've previously had a pearl gourami in a 29 with a beta (and other fish) without incident. The size of the tank, and species of gourami could make the difference.

You wouldn't want to try Osphronemus for example
http://images.google.com/images?svnum=10&hl=en&lr=&ie=UTF-8&safe=off&q=Osphronemus+goramy&spell=1

I wouldn't try it, IMO it would be asking for one of the fish to get hurt. Any gourami small and peaceful enough to not bother the betta would probably get attacked by the betta. I would consider other options.

if you look at my signature line you'll see i have this. I have blue (3 spot) gouramis that do way more damge to each other and pay no attention at all to the betta. The betta has corners set up so he can go in and be sheltered from currents and for him to be fed. occassionally i'll see the betta flare, but NEVER has he done anything but what i call "The Flare and Stare."

all that said, each betta is different and he is smaller than all the gouramis. when i placed him in the tank i was more afraid for him than the gouramis. the gouramis are a gang with colors man.......

i had gourami and betta together in a 10gallon tank before.
gold honey dwarf gourami, small one.
gourami kept on bothering the betta on his fins.
other than that they were fine.