Given incentive enough, the addresses you use are traceable back to you, unless you are a perfect anonymity paranoid with some tech skills.
First at all, if you connect to internet using an ISP service you are paying, the IP you use is linked to you. If i have access to the bitcointalk server logs and your ISP information, then i know who you are. Same is true for a gmail account, an irc connection, or whatever activity you do using your IP. This includes sending transactions. While the blockchain won't store your IP, the bitcoin network, at some point, knew that you used that IP. A determined attacker could monitorize the network gathering this info (or have it stored).
So, let's say you created an address to receive funds and published it in site example.com. If someone can access the logs of example.com and your ISP info, he could know who you are. Your ISP data, in most places, should be law protected and difficult to obtain, in my country a judge has to allow access to it, but the true is that linking a range of ips to one user is not that hard (again, given incentive enough).
There are few ways to remain 100% anonymous. Tor is your best bet, and even using it you still need to be paranoid and higienic to not leak any information about real you.
Note that this info applies to pretty much every activity on the internet, not just bitcoins.