This one would probably do you good ... I have a friend who bought it for use with his Evo 4G and he says it works great...
http://www.amazon.com/Tune-Belt-Incredible-smartphones-protective/dp/B003ZJGZ8O/ref=pd_sbs_sg_2
http://www.amazon.com/Tune-Belt-Incredible-smartphones-protective/dp/B003ZJGZ8O/ref=pd_sbs_sg_2