Gartner has published its 2009 "Hype Cycle for Emerging Technologies", which aims to predict exactly how far away all those awesome-sounding projects, like jetpacks, are away from mainstream acceptance.

The idea is that technologies move through five stages - starting at the "technology trigger", rising in hype to the "peak of inflated expectations", down to the "trough of disillusionment", then gently up the "slope of enlightenment" to the "plateau of productivity".

The report's lead analyst, Jackie Fenn, says: "Technologies at the Peak of Inflated Expectations during 2009 include cloud computing, e-books (such as from Amazon and Sony) and internet TV (for example, Hulu), while social software and microblogging sites (such as Twitter) have tipped over the peak and will soon experience disillusionment among corporate users".

The report, which has been issued every year for 14 years, also predicts that it could still take up to five years for some technologies like tablet PCs, Web 2.0, public virtual worlds and location-aware-applications to gain widespread acceptance.

Some may take even longer. Gartner predicts that Quantum computing, mobile robots and mesh sensor networks are all more than ten years away from being mainstream, and that speech recognition is still 5-10 years off.