I thought Boone just have a spare beret....
This.
I just assumed I got a spare beret from him as a reward for completing the quest. Must remember NOT to try taking his own beret from him, as someone said above...
But I found him so booooring, I dumped him once I found Veronica. Have her kitted out with power amour and a rebar. Man, she loves whacking lumps out of bad guys.
I like to weaken them with a shot or two, then stand back and watch the fun.
As for Ed-E - useful as a pack mule and great perk, but for some odd reason he sometimes decides to attack friendlies. I have to be careful and do a quicksave before approaching bunches of people.
He's sure to pick a fight with someone, and I inevitably get that dreaded "Ed-E has died" message and have to reload. So far, he's done this in Primm, at the 188, the NCR Outpost and Camp McCarren, so it's become a bit of a habit.
I've taken to finding quiet spots outside populated places and making him wait, since he can't behave himself in company.
Edit: Now that I think of it, he freaked out in Repconn Test Site, and that Areosomething industrial park as well. I'm beginning to think he has it in for ghouls....