I don't like the idea of signing in with other accounts. 
You should make it so a person can create an account just for patratzel.
Thanks for the feedback! I'm sorry but, unfortunately, I disagree with you.
My goal is to make a very nice and helpful app that people can use and be able to focus on their drawing. Therefore I don't want to waste time to write all the code to handle signup, account activation with an email, password reset and password change, profile management, and all that. That stuff takes time and I'd rather spend my time writing features!
We are supporting twitter an facebook because that's what I assume most people already have. Personally, I don't ever want to create another account "just for one site" and with yet another password. We can also really easily add all the providers listed here:
https://github.com/intridea/omniauth but we didn't want to clutter the interface.
We already have implemented logins especially for the forum users so you can have the same people you already know on the collab. I don't want to take users away from here, since here is where the community is and patratzel should be just an extension to it. I already PMed code to ptoing and once that is added to the forum you'll just be able to click a link and not even care patratzel is a different application.
For now, since it's in beta testing, pretty please indulge me and try it out, it's really great, I promise

The only information I get from facebook and twitter is that a user with username BLAH and fullname BLEH and avatar BLOH has successfully authenticated. All the logging in and password stuff happens on facebook or twitter. I only get told if it worked. It's really way safer than having your password stored on my server since if you use the same password everywhere and my server gets hacked, you're in trouble.
And, if you don't have either twitter or facebook, I can give you a link that logs you in with the same account as here. The autologin link looks like this:
http://patratzel.heroku.com/customauth/pixelation/autologin/USERNAME/AUTHTOKEN and since it's just a link, logging in like this is a safe process and I won't be stealing your account or whatever. It's in the same league as going to
http://google.com and fearing your pixelation account will be stolen.