I have multiple wall warts.
I've bought 4 full radio systems so I have 4 standard chargers. I started buying 1650 mah receiver packs from NoBS Batteries. They sell a high output wall wart for about $20 so I bought 2 of them. The charger is on this page. http://www.hangtimes.com/chargers.html you have to scroll to find it.

In addition I have a field charger for the times I forget to do the overnight charge.

I vaguely remember seeing chargers with as many as four outputs but they were very expensive.