>Facebook only knows what you tell it. Put up a profile, don't post too much or at all, don't download the app (use the mobile version), don't use facebook connect, and don't use any facebook apps.
And don't use any websites that use any of Facebooks third-party script embeds or use something like HTTPSwitchboard and make sure you never load anything from any present or future Facebook property.
Also don't use any services Facebook has bought or will ever buy (I personally got bitten by WhatsApp and Moves).
Sounds easy. Thanks for the advice.