CIO — There's no doubt that 2009 was a rough year for startups and established businesses alike, but many are holding out hope that 2010 will be different, especially since venture capitalists seem to be loosening their purse strings. Keep an eye on these five businesses that offer fresh ideas to the Web 2.0 arena.

1. Backtype. The Backtype service lets you find, follow and share comments from across the Web. It indexes comments from millions of blogs and social networks, making them available for search based on a keyword or a URL (especially handy for tracking posts on Twitter). It also lets you "claim your comments"—by inputting your usernames for several websites such as Digg, FriendFeed or Facebook, Backtype then attributes those comments to you on your Backtype profile.

2. Evernote. Evernote, a cloud-based service similar to mindmapping allows you to save notes from meetings, photos, documents and more, then organizes them in a searchable way (or you can do that yourself). Evernote recognizes text in pictures too; you can archive notes from a meeting or keep travel documents handy by snapping a photo of them. It also supports Ritescript—a division of Evernote—which is a handwriting recognition software. (Evernote also closed out 2009 with $10 million in financing.)

3. Kosmix. Enter a keyword into search engine Kosmix and it gathers content from across the Web, displaying information in modules such as a general overview of the keyword, news and blogs, company profiles, images, video, latest tweets, related content, reviews and guides, forums, shopping guides and more. Quite comprehensive.

4. Posterous. Posterous is a publishing platform that lets you post pictures, audio files, links, documents and video—but what differentiates it from other blogging services is that it can be maintained entirely via e-mail, on the go. It also lets you post updates to other sites you belong to, such as Facebook, Twitter and Wordpress, so you don't have to visit those sites individually.

5. Shout'em. Shout'em lets you customize a secure microblogging network where you can share photos, files, links and locations with only the people you want—great for businesses looking for a secure alternative to Twitter. Or, if you prefer, you can synch your account with Twitter and Facebook. Shout'em has also rolled out a mobile client for BlackBerry and iPhone users.

Which Web 2.0 companies are on your horizon this year?

Staff Writer Kristin Burnham covers consumer Web and social technologies for CIO.com. She writes frequently on Twitter, Facebook, LinkedIn and Google (GOOG). You can follow her on Twitter: @kmburnham.