How to Photograph birds

With my Canon 350D + 75-300mm (non-IS lens) the bird snap that I click are ordinary, nothing too special, and are less ordinary when left uncropped. I can't afford a 500mm or 600mm f/4 lens or any teleconverter. What should I do... I am using a tripod... don't help me much with the unsharp end of the 75-300mm.

Some tips around here:

http://www.kenrockwell.com/tech/birds.htm

http://digital-photography-school.com/blog/photographing-birds/

http://www.naturephotographers.net

Great forum:

http://www.naturephotographers.net/imagecritique/bbs.cgi?a=vf16

I believe this man has done some great job:

http://www.birdphotographs.co.uk/

Good collection:

http://www.outdoorphoto.com/photos/showgallery.php/cat/all/si/bird