Can I flush the image cache?

[Robert Stuart]

I've changed an image file on my server, replacing it with a file with the same name.

Images are now cached on Brit Modeller, which means I still see the old image, taken from the cache and not the new version. 

 

Using a differnt file name would solve the problem for me, but I know others are using the image file, and I'd like the change shared with them.

 

Specifically, the image is the Eleventh Hour GB banner, which should now show a sponsor.