I use Wikipedia a lot. In many cases, it is better than any other website, is free of advertising, and has authoritative information. It is of great use to people in India, where other forms of reference might be unavailable.
If you can afford to, do consider donating to Wikipedia. All it requires is a Paypal account, and some money. Even a donation of a single dollar would help in keeping their servers running. Millions of people make small edits to Wikipedia, to make it a great reference. A million of small donations can help the website running free of advertising, and make it a model of knowledge dissemination on the web. You could visit wikipedia.org yourself, or click on the link below.
Back in the day, I had a copy of Microsoft Encarta that came free with my sound card. We used it for a while, and were amazed at how much better it was to have an encyclopaedia on a computer. Before that, we had only seen the World Book in other people's homes, and in libraries. And now you had something similar, on your computer! We couldn't even begin to compare the difference in cost (or shelf space). People spent thousands of rupees on the World Book, which mostly sat unused on shelves. We could never afford the volumes, and it felt awkward that there was such a high price on learning. Whatever happened to the zen saying, "When the student is ready, the master appears"?
Many years later, when Wikipedia came on the scene, it changed everything. It didn't matter if you had a powerful computer, a CDROM drive, or money! All you needed was access to the Internet: even a cybercafe would do, and you could access an amazing source of information. All without a username, a password, without payment, and without advertising. The Wikipedia page design has always been clear, crisp and elegant: even when other websites were brutally assaulting us with banner ads, blinking text and the HTML table tag. Wikipedia had more information than any book or CDROM that we had access to. We were hooked, and since then, it has improved every day.
Wikipedia has made such a difference that when I received a promotional copy of the World Book (on CDROM), my father suggested that we trash it. "Who needs it when there's Wikipedia", were his words.