I just shipped a six pack to my brother-in-law so I thought I would report my experience.
I shipped via UPS through one of their "UPS Store" franchises. I chose to ship 5 day ground.
Shipping cost was $14.
No questions were asked in regards to the contents of package.
Beer was reported to have arrived at or slightly below room temp.
If you're concerned about the shipment getting warm, you could place a couple of frozen gel packs in the middle of your shipment. Or perhaps use a white styrofoam cooler instead of a cardboard box.
Your other option is to ship overnight.
I avoid USPS for previous stated legal reasons.
fermenting: Edwort's Apfelwein
kegged: soda h2o, Belgium Pale Ale, SMaSH IPA, Nora Bear's Brown
killed: IPA 'lite', Kölsh
current setup: under review