As part of my "life is still too short" phase, I have splashed out on some more camera gear for my new DSLR. I went for a Canon 55-250 IS zoom -the cheapest one Canon do. It's a bit shorter than the Tamron and Sigma 70-300, but does have image stabilisation, which I have to say, is really quite impressive. You can hear it whirring away and the resulting image is really stable.
Went for the Canon over the Tamron and Sigma as reviews say that the top end of these 300's isn't that great, so you can only get good images up to about 250 anyway, whereas the Canon should do its whole range and stay pretty sharp.
Pricewise, Jessops were selling the lens for £239 which was a bit high, so I bought from a place called OneStop Digital, in Hong Kong for £146. They pay any duty that you may have to cough on import, if you get charged. Arrived within 5 days. Very pleased with the sevice.
So, a good Canon lens for the same price as the Sigma, or about £30 more than the Tamron.
Now I just need to get out and use it!