If you're outside USA it can be pain buy some BTC (well not if need only 3-5 but if need some 100's is it).
Lot of transactions requires payment with methods not accepted in Europe
Exchanges like mtgox requires that you make a SEPA transfer to your account. That's kind of transaction can took up to 3 working days, in 3-5 days prices can fluctuate a lot and I'm not confortable to keep more then few bucks freezed on the account of a exchange (and transferring money back to you can cost a transaction fee).
There are places like bitmarket.eu, in which you place an offer at a choosed price and then transfer the money to the seller that accept that price, but that's kind of exchange have similar or even worse problem: I've placed on 9/19 an offer for some BTCs, after few minutes someone placed a 800BTC offer just over mine. It took 2 days to close all the buy (with 12 different small transactions) and today I've still to receive half of the BTC payed because money are not arrived by friday to 2 of the sellers (I think that it took at least other 12-15 hours to do). That's make me loose a good buy on a site because I don't have enough money to do the transaction
On the other side is really difficult to imagine a way to make transaction fast and secure for both buyers and sellers.