Is it possible to learn ASL online only?

After watching a few (OK, most) Dirty Signs with Kristin videos, I've been inspired to make ASL my second language (other benefits: being able to communicate with anyone, regardless of their hearing ability, being able to notice when people unintentionally sign things, and having private conversations in public or loud places)

So, I was wondering, can I at least teach myself the basics from online resources only? What's out there?