If there’s one major difference between this year’s Web 2.0 Expo in San Francisco and years past, it’s that both the technology on display and the crowds have matured.  Sure, there were plenty of start-ups and 20-somethings, but this year’s event featured veteran cloud leaders like GoGrid and Rackspace, the ACLU (to remind us that online privacy and freedom are part of our civil liberties), and anchor booths from vendors like Adobe and Microsoft.

Media coverage of the event reflected Web 2.0 Expo’s shift from the favorite new kid on the block to the neighbor we all know.  Instead of a stream of articles on cutting-edge technology and visionary speeches, both CNET and VentureBeat opted for photo galleries that fit “news” into the captions.  Some of the heaviest booth traffic could be seen at the Long Tail Pavilion, which featured clusters of start-ups at small tables.

One of the cool things we saw was the convergence between social networking and voice communications. Canadian start-up babyTEL, for example, gives voice to Facebook – literally.  Download its free Facebook app Telephone, and you can speak with your friends free or post voice messages to your status.  New at Web 2.0 Expo is TelephoneAPI, which will allow developers to code this voice capability to their applications.

So, was the show fun?  Well, gone are the days of vendors raffling off cars for attention.  Beyond pens and stickers, giveaways were pretty scarce, which surprised us in the age of the iPad.  In any case, we did see a clever contest from The Planet, which gave a netbook away to the person who could reconfigure a server fastest.  Our pick for best tchotchke of the show was iStockPhoto’s imprinted guitar picks.  Rock on, Web 2.0 Expo!

Here’s hoping Web 3.0 comes soon to heat this sector up again.