I use Flickr a lot for wikipedia articles. I'm a strong believer in creative commons. Many people are generous enough to release their pictures as "attribution only". This allows projects like wikipedia to use their images. (Wikipedia needs the images to allow commercial uses as we give info to anyone - including someone (say) creating schoolbooks in Kenya).

I have been working with the British Museum as part of their collaboration with Wikipedia. Well done BM! Details here.here

If you want to change a license then you can use

Articles I've written based on Flickr pictures include this one of an amazing automata clock

One "snap" on Wikipedia got 3.7 million views. Not bad for an amateur image. Be generous with your images f you can.