Based of my own experience here are some must haves for tech people on the go, in no order at all.
1. Portable Hard Drive (Greater than 250 Gigs)
This is to store files that you can actually use, sure an 8 gig stick would work for most people but your not most people are you? I use my to carry around Minecraft, Utorrent, and large files.
2. Camcorder (1080p is cheap now)
Who knows we you'll need to show someone how to do something to their hardware? I have a Kodak Zi8.
3. PC clean up kit (Microsoft Security Essentials, Firefox, Chrome)
This goes into your Portable Hard Drive, it saves grandma's computer a lot.
4. A basic understanding of 32 and 64-bit machines and what OS they are running (not all software will run on 64 or 32 or different OS's)
About 1/3 of all files download will ask what your hardware is, I have a 64-Bit Windows 7 Ultimate, some thing will not work with my computer. More on this for another post
5. Basic skills using Adobe software (photoshop, illustator, dreamweaver)
If you want to build a website, edit photos or make a poster learn these. Adobe is the god of design.