Lots of online services, from hosting to DNS to VPNs accept bitcoins. Several online stores accept them, and they're a good way to donate to, eg, Wikileaks or the Manning Defense Fund.
As far as the cost of using them, while it is non-zero, some of us just want to do our part in establishing a currency and surrounding ecosystem that is free from gov't, corporate, and other meddling. Thus we accept the small hit in price.
Several friends of mine prefer to pay for their VPNs anonymously, they get two VPNs, pay with bitcoin, don't give their name to the VPNs, and tunnel one into the other for pretty much complete anonymity online, provided they don't do something stupid like log into facebook from the VPN.