Which contact method?

How do you determine which contact method to give out to someone? Do I give them a landline number, a mobile number or a VoIP number? My personal email, my business email, my Skype ID, my Twitter ID, my Facebook page ...

Whichever number or method I pick, I'm assuming the one I picked is also convenient for them. Alternatively I could just give them everything and confuse them completely!

I'm thinking about the power of an alternative that will soon be available - .tel from Telnic. More on this shortly ...