Just for future reference:

Under a debian system (I'm on ubuntu) with Apache2 and the deflate module already installed (which it is by default), you can enable deflate compression in two easy steps:

a2enmod deflate
/etc/init.d/apache2 force-reload

And you're away! I found pages I served over my adsl connection loaded MUCH faster!

On Ubuntu with Apache2 and the deflate module already installed (which it is by default), you can enable deflate gzip compression in two easy steps:

a2enmod deflate
/etc/init.d/apache2 force-reload

And you're away! I found pages I served over my adsl connection loaded much faster.

Edit: As per @GertvandenBerg's comment, this enables gzip compression, not deflate.