Making money from your interests

Over the last couple days I've once again been considering a little online business on the side. Right before I moved to Scotland, I had been the middleman between and Aprilia dealership and Formula SAE teams selling them crate engines. It was pretty sweet as I made $150 for each sale. I ended up selling 8 engines in a matter of about 5 months and all I had to do was post on a forum and then answer some emails. From that, I started to plan a website called FSAEnetwork.com. It's still up, but nothing more than a welcome screen and an empty forum. I realized too late that the market just wasn't there to make decent money for the effort. For 2008, I've committed myself to finally getting into investing. I have a 401K started, but I'm interested in really learning how to invest in stocks, bonds, etc. I've picked up a couple books, and I've even set up a practice portfolio on CNNMoney.com. Starting at January 1st, I've picked some stocks that I think will do well, but so far the market is just shit. One day I was up about $200, but most days it's been negative. I know investing is really about the long term, but it's been fun to watch so far. Probably because I don't have any real money invested yet. I need to finish reading my books so I can figure out which stocks are really a good value instead of just a good guess.
The North American International Auto Show a.k.a. the Detroit Auto Show has been taking place this week. I've been reading hyperlinks on Google News over the last few days. The main theme this year has been 'green', although not surprising considering high gas prices, global warming, and the passage of the new energy bill which will force manufacturers to increase their Corporate Average Fuel Economy. Most of the manufacturers have been announcing hybrids or diesels depending on the vehicle. I personally feel that hybrids are good in small cars in town in stop and go traffic, but diesels make more sense in big vehicles that travel the highways.
With all the manufacturers getting ready to release cars or trucks with diesel engines in them, I've once again been considering starting a website centered around the general topic of diesel engines, which obviously is a larger audience. This would take a pretty good time commitment, so I’m putting some thought into it. I might make a tiny commitment and just start another blog with news feeds from various diesel sources.