Spider banning

Is there an easy way to stop all spiders except google, msn, yahoo and ask.com via robots text?

It seems that there are so many data gatherers about these days, that offer very little in return, a simple robots text ban would reduce band width, increase page load times and you will still get the same search engine referrals from the likes of Google.
Possibly better Google ranking if your page loads are a lot faster.

Any help or feed back on this one would be much appreciated

The sort of gathers you are talking about tend to ignore robots.txt files so it would be no good... Don't get me wrong it is possible to deny * then set google, msn, yahoo and ask to allow but I am not confident it will help in your situation.

The only way to block rouge bots is to ban then via IP address or Useragent in your .htaccess file HOWEVER this can easily be messed up and end up blocking legitimate bots or users and the more you add to you .htaccess file the longer it will take to process and would actually end up effecting site speed if you let it get too big.

It's basically a waste of time.

You basically have 2 options--
set a whitelist, block everything else
set a blacklist, block everything else

Either way, you need to account for ALL good things, or ALL bad things.
Something that is simply not possible.