Fiddling around with the new version of the gmail client at lunch time I found something that I've been desperate for in the past! When you're viewing an email, press the Menu hardkey, select More... and choose "Select text". Then simply drag your finger over the block of text you want to copy. It's rudimentary but it works. Unfortunately it doesn't work on the quoted text area when you are replying to an email, but hey, it's a definite improvement on going to the webmail client.