I took a look at Gartner's Hype Cycle predictions for 2008 the other day after missing it in 2007. I've followed it for years but took a keen interest in 2006. I picked up again on the 2008 version via Neville Hobson who has been tracking it over the last few years. I noticed Idea Management suddenly appeared in 2007.

Funny that it should only appear in 2007 considering idea management has been around for decades. It must mean Idea Management specifically related to WEB 2.0, I thought. So I checked the report. In the report, the description falls under the title of Idea Marketplaces and is defined thus: " Idea marketplaces facilitate the exchange of ideas and talent between owners and acquirers. Owners can make their ideas and talents visible and available. Acquirers can discover and gain access (via purchasing, licensing, open sharing or other arrangements) to the ideas and talent they need. Note that idea marketplaces are business organizations that are users of Web technologies to support their processes." Crowdsourcing is treated separately under the report but appears inter-related.
We have been playing our own little role with our netoVation (Networked Innovation) prototype which we are now working on realising in production environments. Watch this space for more news on that front soon!
Some additional thinking in that area is reflected in the below diagram:

A fundamental point is that successful Idea management needs a combination approach of structured controls and freeflow input, something akin to the top-down, bottom-up approach. This is the human element. On the technology side you have all of the lovely social elements depicted.
It's great fun working on this and getting to implement it at organisations and I foresee great things ahead for this rapidly growing niche area of social computing. I'll end on a quoted prediction from the Gartner report:

In the future, organizations will leverage idea marketplaces as a provider and acquirer of ideas alike. Such higher leverage will materialize as innovation and idea-generation processes mature in a significant number of organizations. Expect innovation maturity to proceed at a moderate between 2008 and 2012. At the same time, expect that global competition and participation will accelerate development of best practices in using idea marketplaces.