I'd like to get a fish eye lense for my 350D...I love the style of pictures they create. I'd like to get one fairly cheap, but I do realise this is hard to achieve. So, does anyone have any ideas where I can get a fairly good one (fairly low range, 15mm perhaps and aperature, f2.8 preferably)

UK based and would like this fairly soon.

EDIT: Although pricey, I think the Sigma 8mm f/4.0 EX Circular Fish-Eye would be a good candidate. Am I right?

Since you are on the Canon side, that would be the lens I'd buy.  On Nikon/Fujifilm side, I'd buy the Nikkor 10.5mm f/2.8 even if price is double

So yeah, for your Rebel XT, the sigma is a good choice

Thanks Pink Floyd...funnily enough, I've been listening to Pink Floyd all day in work on my MP3 player! One ear phone in obviously so I can hear the phone etc! Anyways back on topic.

I've been looking on Flickr and Pbase for good example shots of this lense and so far, this one stands out for me - http://www.pbase.com/eminilia/image/59177965. Do you know of any good shots taken with this lense in use?

I will keep that in mind as well, since I just purchased a Nikon D70s. I figure that glass is a lifelong investment so as long as I take care of my glass I am set for life.

How about the Canon FishEye 15mm f2.8?

Well 15mm is not too fisheye for me. It all depend on the focau lenght you need.

I agree, the whole point of a fisheye is to get the widest results that a ultra wide angle lens cant captures. I.E my Nikon 12-24 is ultra wide angle...but an 8mm fisheye will go wider..just give you that bubble look.

If you don't mind a completely manual lens (exposure, focus, everything), you could take a look at the Peleng 8mm fisheye. It's usually M42 mount, so you'll need an adaptor to fit it on your camera. Apparently it's pretty high-quality, but not the most convenient thing.