Themes like 'semantic web' or 'recommendation engines' are still very pertinent.
Google results for 'PhotoSynth web 3.0':
"Providing a glimpse of what we might expect to see from Web 3.0"
"I am sure that after the launch of Photosynth, we will have a new web all the way and may be we'll call it Web 3.0."
"Web 3.0 Explainded"
"Related Tags: facebook web digg social networks web 3.0 technology"
"This is incredible. Amazing. The conglomeration of social ... This is web 3.0, the semantic web in the making."