Tagging (or in more conventional English - labelling) images, all very Web 2.0 but not always so interesting to do. It is however important for search engine semantics because as yet they tend not to be able to actually identify what the content of a picture is. Google image search et. al. tend to look at the text on the page with the image on, inbound links, its filename and so on. When you search for a "house", you're actually searching for a picture on a page with a lot of house-content on, which likely will be a house but on the other hand it could be, well, anything. What you really want is for a human to hand-label each image with "house" if it itself is a house and "donkey" if actually it is a image of a donkey on a page about houses.

Considering the uber-billions of pictures on the web, you can see it is quite an arduous, tedious task for some poor search engine employee to do.

As ever, Google has managed to persuade squillions of users to enthusiastically do their dirty work for them with a giant smile upon their face. It even has a "beta" label on it to fit in with the rest of their services. Presenting Google Image Labeler: let the public help Google label images out of the kindness of their heart to get better searches and of course earn 1 point more than their fellow geek-taggers.

You will be randomly assigned a partner. A random image pops up and you have to type in what you would consider a decent label for that picture would be. Simultaneously your partner sees the same image and does the same thing. Keep battering in more words to describe the picture until - ding - you both come up with the same word somewhere along the line. That word, given it came from two probably unrelated people potentially continents apart, is considered to a reliable descriptor and hidden away inside Mr Google's internals. You get some "points" and the game begins again. But hasten! You only have 90 seconds to get as many done as possible.

Whilst it does sound like rather a tedious enterprise, it is fairly addictive. Absolutely fine for a quick 90 (or 180, 270 or 90,000,000) second break in the working day.