I was just reading Seth Godin's excellent book, "Survival Is Not Enough." Ok, fine, I was listening to the audiobook. But at least he reads his personally! In any case, he puts forth a great idea: Have all the salespeople in the office record their calls. This is legal in most states, but check to be sure. Then, once a week, each salesperson burns their 5 best calls onto a CD, and once a week, small groups of 6 or so salespeople play and listen to each other's CDs. Finally, once a month, create one CD containing all of the month's best calls and distribute it to everyone.
This is an excellent way to stay fresh and learn new things. As salespeople, we tend to stop learning once we become experienced. This is a great way to avoid falling into that trap.