A friend of mine recently gave me a Nite Ize "Clip Case Cargo Wide" case after receiving an Otterbox Defender for his Droid X for Christmas and I put it to use on my EVO. It fits my Evo suggly and I have an Otterbox Commuter case on my phone. It slides in without being loose or falling out. You have to put it in upside down but that was how I always put my phones in my holsters. I have it shown here right side up. The reason it goes in upside down is the flap on the commute's case gets in the way if you put it in correctly.
Otherwise the case features a very strong nylon plastic captive clip that rotates. A bluetooth ear roach pouch on the back, and a slot for credit cards/IDs/hotel keys on the inside.
The evo is a little tall but the velcro catches securely. I am on a job assignment this week and was climbing around in truss and never felt that I was going to loose my phone or that the holster might come off of my belt.
Pluses: extremely rugged, secure, plenty of padding for protection or knocking into objects, very solid clip.
The only minuses are: the case is a universal style so it is a little bulky, the case closes over the EVO but it is a slight stretch, I prefer magnet closures over velco, accessing my phone numerous times is taxing with the constant ripping-of-velcro sound.
oh and it was only 15.00 and even
less on amazon!