As a user, how do I know I'm signing in to a geniuine service?

So far live IDs have been used primarily by Microsoft properties, meaning that it was easy to spot fake log on screens.

If more sites and apps start using live ID to log people in, how will I as a user know that I'm submitting my credentials to a genuine service?

[280 byte] By [ReljaMarkovic] at [2008-2-22]