Good Sam Mail Service - based in Pensacola, FL
UPS Store Mailbox - mail-box, mail-forwarding, & more at any UPS Store location
Mail Forwarding Services - based in Jefferson, OR
Escapees RV Club Mail Forwarding Service - http://www.escapees.com/mailforwardingservice.asp??? : "The catch with them is that they require anannual (or Lifetime)Escapees Club membership fee in addition to a mail servicemembership fee plus postage."
Alternative Resources Mail Forwarding - based in Sioux Falls, SD
MyDakotaAddress.com - based in Madison, SD
America's Mailbox - based in Rapid City, SD
Your Best Address Mail Forwarding Service - based in Sioux Falls, SD
Voyagers Mail Forwarding Service - based in the FL keys
http://www.sbimailservice.com/index.html - St. Brendan's Isle (FL based)
Check out www.retirementliving.com for a comparison of tax situations (ALL KINDSOF TAXES) for all the states.