I've been carrying an M9 open and concealed (99% concealed) for about two years now. Sure, it's on the large side, but it can be done. If your clothes fit properly or a little bigger, than you shouldn't have a problem doing it. I do have a smaller gun or two that I can waistband or pocket carry if need be, but the Beretta gets carried 99% of the time and I carry where ever and when ever I legally can.
There are good holsters out there for it. Comp-Tac and Blade Tech, Raven, or Galco come to mind.
But I've been using one of these for two years.
http://www.berettausa.com/products/nylo ... 92-series/ I bought one on a lark when I was trying to decide on a good permanent holster to use. But in the end, this one works well and is solid for the price.