Online collaboration is one of those ideas that just won’t go away, which is probably a good thing.

If you’re a small firm with employees or partners working in different offices, or if you need to work more closely with customers or suppliers, you really should be taking advantage of this technology.

Online collaboration tools, for which you typically pay by the month per account, can save travel time and costs, increase productivity and make your firm more agile and flexible. How do they work?

Some applications let you set up Web conferences to link participants anywhere in the world so that everyone can view the same documents or information in a browser window. You could make a PowerPoint presentation to a virtual group just as you would in a live meeting. Participants typically need only a computer with an Internet connection and a browser.

Other services include teleconference or video conference as well as instant messaging capabilities, or can be used in conjunction with some other conferencing service. And most allow you to collaborate on editing or marking up documents in real time.

Another class of solution – blogs, wikis, file-sharing tools – establishes a virtual meeting place where work teams can post documents to share, manage projects and engage in forum-style, non-simultaneous conversations.

But which product/service should you use? The market is already crowded, and almost every week, it seems, new software-as-a-service (SaaS) collaboration products appear.

The latest entrant: IBM with LotusLive, a new platform for consolidating and integrating collaboration tools.  It joins other big players: Microsoft, Google, Cisco and Citrix.

And then there are a bunch of smaller, independent companies, often formed specifically to bring their vision of online collaboration to market, companies such as Central Desktop, CallWave and Yugma. They often offer stripped-down free versions of their services that might be enough for very small firms.

Don’t ignore the big players, though. They may have started out selling mainly to large enterprises, but they’re very interested in talking to small businesses, too.

LotusLive

LotusLive looks promising, and you don’t have to have IBM’s flagship Lotus Notes e-mail and collaboration product to use it, although it helps. It also integrates with other applications, including SalesForce.com.

LotusLive so far incorporates Sametime Unyte Web conferencing, and LotusLive Engage, a new solution that works with and builds on Sametime, offering business/social networking and project-management features. Engage is due out early this year but it’s in open beta now – you can test drive it for free.

Sametime is a SaaS version of an earlier IBM client-server Web conferencing product. It’s completely browser-based and lets you share your desktop or a specific application, or you can simply “publish” a few documents to view during a conference.

Sametime is easy to use – participants don’t have to download anything. It comes with all the security you would expect from an enterprise vendor, yet it’s reasonably priced – $50 to $100 a month for unlimited use.

IBM charges nine cents a minute per participant for toll-free teleconferencing – but you could also use some other less-expensive audio conferencing service, including Skype, the online phone service from eBay that provides free Skype-to-Skype calling and very low cost audio conferencing.

LotusLive Engage will let you manage contacts and schedules, create communities and work groups, adding members from your Outlook or Lotus Notes address book. You can also post files to share, create forms to fill in, collaboratively build spreadsheet/databases, launch Sametime meetings and create and manage activities.