Hi Gregg.
Typically, if you're not running snmp v3, there is no way to encrypt community strings in a config file.
If you're not running snmp v3, SNMP community strings are transmitted in clear-text when doing SNMP operations anyway, so obscuring it from a config isn't gaining you much.
That said, SNMP v3 is the way to go if this is a major concern.
HTH,
-Joe