I picked up another bitcoin this week. I had originally wanted to buy when they were worth < $100. Now they're bumping up against $1000. I'm not too worried about them gaining or losing value, I just really wanted to see how they work.
The hardest part has been for normal users to convert dollars into bitcoin. They're just not the easiest thing to purchase. You've got to do a bank transfer to someone that can handle it for you. Trusting some 3rd party on the internet with any bank details whatsoever is always a bit of a leap of faith. I set up an account on Coinbase, which keeps the process fairly simple. The only downside is that it can take almost a full week for your purchase to go through.
Once you have a few bitcoins in your wallet, it becomes clear how revolutionary the system is. You can quickly bounce it around different wallets, in increments worth fractions of a penny. Bitcoin or a system like it is definitely going to take off, there are just too many advantages for it not to.
One last note, Jaimie just found a very good / simple explanation of bitcoin here.