And talking of image formats...

Jacko, if you knew Russian language, i would point you to www.design.ru/kovodstvo/

In couple of words, JPEG is more preferrable for photos, hi-color images, etc. Its feature is in ability to decrease file size by making picture worse (in mathematical meening). When you make .jpg image, you should choose optimal ratio quality/filesize so as decreasing of quality was visually insensible but filesize was smaller for faster downloading.

As fiddleabout said using .gif is better for lineart, logos and any other images where are less than 256 colors. CIF format stores image as a string of "pixels with specified lenghts" .
Gif is good for making animated images, banners.

Heh, it's more difficult to find such info than 5-6 years ago ...
PNG and GIF compete hardly now. Which one will win - time will show.
Funny link -> burnallgifs.org/

Wo AEuropean that's the ticket - ta.

You can get another view about PNG from www.w3.org/Graphics/PNG/ and there's plenty of links from there which talk about image formats.

Ta Fiddle

Web browsers support only jpeg and gif (some support png too)

In general use jpeg for photos and gif for lineart/logos etc.

Tif is needed for some ocr software and I'm not sure about eps

Could anyone point me to a website that explains when I should use .gif format instead of .jpeg, or .tiff or .eps...?

I say website cos I expect it's all so basic that it's not really worth anyone bothering with.

(Humour me chaps - I'm on my nth glass of Rioja)

Ta