Home repair. It's a natural partner to HTPCs - very DIY. You could hire/buy, but it would be very expensive. If you do it yourself, you can get exactly what you're looking for. I play with the PC stuff in the winter when it's too cold & rainy out to work on the house, and the house in the spring/summer.
I've been instructed that I'm repainting half the darn house before baby #2 arrives [in 10 weeks], and in the early summer I am to build a brick patio. My wife says that this year the HTPC project needs to go dormant somewhere around 3/31, cuz she'll be using me pretty fulltime around the clock then.
My main other 'time and money flows into' hobby is ham radio. NTSC is much more fun to send than to receive. Others include roller coasters, antique television sets, and 'a few cool toys on Ebay that I had (or wish I had) when I was a kid'.
Radio control flying bits (helis / planes / weird stuff)... Used to be involved with Hangliding / paragliding / skydiving / glider flying at various times in the last 10 years they are all out due to my current location but basically I get a kick out of being airborne and second hand is the best RC can offer...
Publishing my own web page as noted on Audio/Video data, super-efficient house design (insulated concrete domes), alternative energy, rainwater collection, organic farming, super-realism (3-D graphic artwork in oil, acrylic, CAD...), super-efficient transportation (pedal, gas or electric powered), RC electric sailplanes....
Funny stgdz you mentioned DIY speakers - I have A TON of info and will be putting up a web page soon for that. I wanted to go with a 4-way all 1st order xover ceramic spherical design - but headphones really sparked my interest.
A forum community dedicated to home theater owners and enthusiasts. Come join the discussion about home audio/video, TVs, projectors, screens, receivers, speakers, projects, DIY’s, product reviews, accessories, classifieds, and more!