Adobe is taking Acrobat.com out of beta on Monday, and turning it into a business with paid user accounts. The service, which has more than 5 million registered users will retain its free version, however there are now usage limitations on certain features which can be unlocked by upgrading to one of the two new premium plans. These can be purchased on a monthly or yearly basis and cost $14.99 or $39 a month, or $149 or $390 a year respectively.

The "premium basic" plan allows for 10 PDF conversions per month, as well as up to five meeting participants though Adobe's ConnectNow tool. The "premium plus" plan dials that up to unlimited PDF conversions, and meetings with up to 20 users. Both premium plans also gain phone and Web support. In comparison, free users will only be able to convert five PDFs, and connect with two people at once in ConnectNow, which is just one less connection than users were able to have during Acrobat's beta period.

Along with the move to paid accounts, Acrobat.com is getting a new collaborative app called Tables that handles basic spreadsheets. Just like Buzzword, Adobe's online word processor, this lets multiple users work on a spreadsheet at once, as well as track revisions and roll back to earlier versions.

In a call with CNET News last week, Eric Larson, who is Adobe's director of product management and marketing for Acrobat.com, told me that Tables is not quite ready to replace Microsoft's Excel, which is why it's being rolled out in Adobe's Acrobat Labs section first. Larson did stress, however, that it will allow users to do things Excel can't, like see where other people are on the document, and provide a subtle warning when users are making a visual change that will affect others.

Little things that users are used to doing in normal software, like changing column width or sorting order, yields a small warning message that tells them to think twice if there are other people working on it at the same time. It also provides the option to switch to "private view," which lets users make edits without the changes going live to the main document. Adobe is hoping this type of work flow will cut down on the e-mail overload, and versioning problems that typical office software creates.

I gave the tool a spin over the weekend, and for basic spreadsheet tasks it's quite nice. Unlike Google Docs, which opens up to a sea of white cells, Tables opens up to just three columns and five rows which can be expanded one at a time. It's also incredibly responsive, letting you re-organize, and snap around columns and individual cells as if you were using desktop software.

Included are a wide range of formulas, however there is not yet a way to reference individual cells, which may be a show-stopper for some financial applications. You can, however reference entire columns.

Will this be enough to woo users to pay up who were previously getting some of these things for free? Adobe seems to think so, and is still allowing users free and unlimited access to Buzzword, Presentations, and now Tables. The big thing that changes with today's news is an expansion of the the services that let you share what you've created with these free tools, either by converting files, or talking about them in the live meeting solutions.

Adobe is eventually hoping to get Acrobat.com beyond the browser and get its AIR application up to parity, so that users will be able to use these same apps, and access their work off the browser. The company is also trying to get people access to these files and applications on mobile devices, where they'll be able to make edits and even create new documents, although this isn't coming until later this year.

Following that, Adobe is working on an upgrade to its PDF technology that will show others when a change has been made by anyone else who is collaborating on it. When it finds that out, it gives them the option to update to the newer version, similar to what happens when a developer makes a change to a software application.

With Acrobat.com, Adobe is coming a little late to a game that Google, Zoho and ThinkFree have been running for years, and that Microsoft is set to join very soon. What may make the difference is that Adobe can work these products very deeply into other pieces of its software. Whether that ends up being a liability compared to competing solutions that remain Web-only is unclear.