If fonts are your main concern, it may be best to browse using a cleanly-installed system or Virtual Machine.
Other potential (partial) solutions:
Tor [https://www.torproject.org/] - when used carefully, can give you a high degree of anonymity.
Disable Flash and Java to minimize font leakage.
Use Firefox extensions such as FireGloves [http://fingerprint.pet-portal.eu/?menu=6] to alter the User Agent your browser presents.
And don't forget about all of the other basics such as IP address (use Tor, VPN, SSH tunnel, or other proxy), cookies and other saved state (clean your browser of these frequently), and the sheer numbers of trackers that follow you as you browse (consider strong tracker blocking via hosts file, browser plugins, DNS, and/or proxy).