My initial reaction is: "Scumbag permissions":

For Twitter signup:

> This application will be able to:

> Read Tweets from your timeline.

> See who you follow, and follow new people.

> Update your profile.

> Post Tweets for you.

> See your email address.

For Google it wants to see my email contacts.

This is very off-putting and makes me wary about giving you my email address.

The privacy policy (which alleviates some of my fears) should be linked much closer to the signup box rather than at the bottom of the page.

Also: it's asking for a password in a way that doesn't trigger Chrome's password manager.