1. Talk to yourself in the shower - that way no one can hear you and you won't be embarrased.
2. Talk to yourself in bed.
3. Make friends with a foreigner
4. Watch movies/plays/listen to music and sing along...read along..that always helps with pronunciation
5. Try to go to a summer camp in America (if you have the money). Usually, if you go to a summer school in a university, the visa is easier to get.