If your bro has been on a deployment before, he's probably got the mission gear thing down. As such, i'll comment on luxury items.
HD based MP3 player filled to the brim. A must if you are a music fan.
Laptop computer with DVD player, IBM and apple are bullet proof and proven desert survivors.
200GB external firewire/USB2 HD with tons of ripped movies and music.
1GB+ PQI Intelligent Stick or Corsair USB memory devices, once again, survivors.
Adidas sandals with the hundreds of little nubby things, great for wearing in the tent. It masassages your feet and keeps them in good condition. Send him a second set halfway through, the little nubs start to break off.
Boxes and Boxes of 123A lithium batteries. I brought one gross, used about 60 myself and sold the rest priced according to the laws of supply an demand. That is, HUGE demand with me as the only supply :)
Camelbak cleaning kit
OTIS 5.56/optics cleaning kit
If he's an NCO, a rugged PDA can be handy for storing soldiers info, regs, FMs and the like. You can read e-books with them too.
Other than that, I doubt he'll have much time for anything. I brought a game console with LCD screen and played it maybe 3 times.
EDIT: I-Go universal power system. Can power his laptop and any concievable electrical accessory. Accepts 100-250VAC 50/60Hz and doesn't have a problem with shit tastic power fluctuations. Worth its weight in gold because not only does it work anywhere, but one adapter charges everything, saving weight and space.
Oh yeah, your whole family needs to get
PGP and generate some huge assed keys. It is estimated that stuff encrypted with a 2048 bit key would take 40 quadrillion years to break just one message with todays tech. PGP goes to 4096 bits. You should read some FAQs on it, but basically it goes like this. You generate a key pair on your computer, a private key and a public key. You send everyone your public key and get everyones public keys from them. Keep the private key only on your password protected hard drive and on a backup flash media that you keep on your person. You type up a message, PGP encrypts it with a symetric key based on your random keystrokes, then encrypts it with the recipients public key. You send the encrypted file to them and they put it on their USB drive. Then, the recipient moves the file to his computer and decrpts it with their private key. 2048 is military strenght, but obviously you don't send mission plans over it. It is really easy to use, free and good protection against terrorists targeting your family while you are away.