Here's a short list:

Macintosh upgrades: Why just fix your Mac, when I can make it better. More RAM (you can't be too rich, too young or have enough RAM), bigger hard drive, faster processor, extra video card, a new peripheral, or installing or upgrading new software;I can do all of that, under many circumstances. The details determine the options, of course, but we can talk about that.
Graphics troubleshooting: having spent a few years in the graphic industry, I've solved many graphics problems, and can teach you how to avoid the various pitfalls of print and web graphics design, including font and picture format issues, technical requirements, etc.
I also do some graphic art and design, but I'm no threat to put any established designers out of business. I do a fair amount of subcontracting to other graphics professionals.