Big news today: Evernote is now in Open Beta and we’ve rolled out many changes, including premium accounts.

Four months ago, we introduced the invitation-only private beta of the new Evernote service.  Our goal was to get about 10,000 people to use the system so we could fine-tune our servers and try out new features.  We were blown away by the response and watched with equal parts of glee and horror as the closed beta users count passed 10,000, then 25,000, then 50,000…  By the end of the four months, over 125,000 people had participated in the closed-beta!  Luckily, our hardware, software and team held up with only minor incidents of spontaneous combustion.

Since launching the closed beta, we’ve released new feature updates virtually every week and today we took the biggest step of all: Evernote is now open to the world!  You no longer need an invitation to create an account.  Anyone can sign up right from www.evernote.com and start using your shiny new external brain in 60 seconds.

We now have two types of accounts: Free and Premium.

Free users will keep all of the features of the closed beta, including automatic synchronization between Windows, Mac, Web and mobile phone clients and advanced image search.  There is no limit to the total number of notes that you can store.  Free accounts can upload up to 40 megabytes of new notes into the service every month.

For $5 per month (or only $45/year, because we’re bad at math), you can upgrade to a premium account.  Premium users have their upload quota raised to 500 megabytes of new notes per month and get a number of other goodies, including enhanced security through SSL for all data transmission (free users only get SSL for login), priority access to the recognition queues (for much faster image recognition, even during peak busy times) and premium customer support.

You can try out a premium account at any time without worry: if you ever decide to go back to a free account, you’ll still have all of your notes (you’ll just go back to 40 megs per month for new notes).

We’ve also got a limited number of stylish Evernote launch t-shirts (pictured above) that we’ll give away to one-year subscribers until we run out of stock.  I’ve been wearing one around the Las Vegas strip lately and getting more compliments than I deserve.  People just like swirling pink elephants.

For more info on free and premium accounts, check out http://www.evernote.com/about/premium/.

Two more big changes are going to get their own blog posts soon, but you can try them out right away: we’ve got a brand new web clipper and a completely redesigned web interface.  I think you’ll like them.

We’re excited (and a bit scared) about abandoning the relative shelter of the private beta for the open waters ahead, but if we’re really going to expand everyone’s memory, we’ve got to let everyone in.  As always, let us know how we can improve.  We’ll be keeping up the rapid pace of new development throughout the open beta.

Thanks to the 125,000.

Wish us luck!