Bands that have toured with Placebo? Around 2000?

Answer 1

Idlewild, Six by Seven, Stereophonics, Eminem, Slipknot, Guano Apes, Muse, Rollin's Band, Weezer, Underworld, Beck...
There are several others that you can look at for yourself at the following link: http://www.placeboworld.co.uk/tour/2000dates.html

You can also look at the previous and later tour dates, just look at the archives.