Here's a Blade-Tech Kydex holster with a fast on/off Tek-Lok clasp. (It's a standard left-hand holster that I often wear IWB on my right-hand side.)
Here's a heavy leather Wm. Tucker, 'HF-1' holster. It's highly concealable, very comfortable to wear all day long, and very slow to draw from.
There are a lot of excellent holsters out there. Two other holsters that I really like are Kramer Handgun Leather's #3 IWB, and Comp-Tac's Minotaur.
Kramer #3 IWB