With respect to the CCW holsters, here are my observations:
One mistake I never failed to make with concealed carry holsters was NOT buying my pants one size bigger to accomodate the bulk of the pistol when worn in a IWB holster.
Once you do that many of the problems of the gun sticking out disappear. I would advocate getting one of the newer stiff leather holsters that allow you to re-holster. I always liked the suede variety - but they don't do much for holding the pistol in, and reholstering is impossible. I would also buy some square cut Hawaii style shirts and forget about the "T" shirt when carrying. Not only will the square cut button shirts conceal a pistol better, they are cooler.
I think that a pager holster and the ankle holster are just too complicated to be of much value, especially if you are carrying to protect against a "sudden" unexpected attack. Pager holsters and the ankle rigs are fine for cops to carry their BUG, but I think less than ideal for civilians.
The best holster in my opinion is leather, form fitting to the pistol it carries and free of thumbsnaps. It should be worn on the outside of a stout leather belt on ones strong side. I like a holster that does not drop below the line of the belt - but that is very hard to find. With such a rig it is necessary to dress in layers to conceal it, but that is fairly easy to do. The difficulty of CCW is that you have to dress around the W, which becomes more difficult to do the less you wear!
The only alternative is to go to smaller guns like the Seecamp, but while fun to play with, are best used by LEO's as back up. You can learn to shoot one well, but in a high stress situtation I would not bet that I could properly employ a pistol of that size at any distance beyond five feet - and that is too close.
I did not mention the pocket holster or the shoulder rig. But my expierence with those is limited. Prehaps someone else will offer observations on the best of those.