robots.txt

I'm not bothered about restricting any spider's from accessing my sites but everytime they request robots.txt (which doesn't exist just now) I get an error in the logs too.

Can I just put an empty file up as robots.txt or is there some way I can write "welcome, come on in everybody" in robot language :-)

empty file in the root works fine, although personally I dont think you need it. Spiders are a lot more persistent these days