I, personally, wouldn't invest money in trying to convert that bike into a commuter (unless you plan on riding mostly on bumpy dirt roads/trails for your commute). Save your money (the money you would've spent trying to convert it and some additional money / sell the bike) and invest in a practical road bike for commuting. Even if you did convert it, it'd never work as well as a true road bike (too heavy, too much wasted energy with the front and rear suspension, probably not designed to easily take fenders or racks, etc). If it were me, I'd just use it as is (inflate the tires to max recommended pressure) while I saved and researched for a real road commuting bike. While doing this, you'll probably discover whether or not bike commuting is for you. You'll get experience riding in traffic, carrying stuff, working on your bike (for the inevitable flats / maintenence that's required). By the time you have enough saved, you should be in much better biking shape, you'll have a much better idea of what you want / don't want in a commuter, and if you find out that bike commuting isn't for you, you're not out any money. If you've gotten used to commuting on that beast, moving up to a real road commuter will feel like going from an overweight, underpowered, overly plush (read energy sapping), slow, impracticle vehicle to an efficient, practical, FAST (in comparison) real road bike. You can always keep the cadillac and use it for it's intended purpose - mtb.