This is my first post on these forums, so I'm sorry if there's already a thread about this, but I've searched most the threads already and haven't found an explicit answer, so here it is:

I'm a college student who rides for fun. Biking is my main form of transportation (I go to school in Boston and don't like the T) but mostly I just ride for fitness and because I enjoy it. I've been riding road bikes for years - never as a serious racer or anything - but I'm very at ease on two wheels. Recently, some friends who ride fixed gear convinced me (by letting me try their bikes!) to convert my road bike to fixed because of the interesting feel, better traction, lots of fun to ride, etc. etc. (you know all the reasons already, I'm sure )

I've picked up all the components that should be necessary for the conversion, and I'm ready to start building in a week or two. I'm really excited to get out there on the conversion and start learning, but as lame as this may sound, my parents are uncomfortable with the idea (particularly because of the brake situation) and I want to put them at ease if I can.

For me, a big part of the appeal of a fixed gear is the minimalism of it - I love the uncluttered look of the bikes, and love the idea of it being light to carry up stairs, etc... Everything I've read would suggest to me that a rear brake is superfluous on a fixed gear, so I'm ready to toss it (I know what you're thinking, but don't worry - I always wear a helmet, and I plan on running a front brake) but my dad, who was way into road bicycling back in his day, can't be convinced that this is safe.

Am I misguided in thinking that a rear brake is unnecessary? If it truly would be an asset to me (I'm a conservative rider to begin with - no traffic dodging here) I'm prepared to suck it up on the aesthetics and keep it as a safety measure, but I'd really prefer to go with the minimalist look of a front brake if it's safe. What's your take on the rear brake? Can it be safely scrapped, given that I'm a conservative rider in a relatively flat city? If yes, does anybody know of any evidence to help put my parents at ease? Sheldon Brown actually has a whole page written on his take on the rear brake on a fixed gear (as unnecessary) so maybe that's all the proof I need, but I thought I'd ask anyway.

Thanks for the help!