The political spectrum through red-state glasses

There are some people who, despite possessing more than a little wit, are so focussed on the so-called left-right divide that they classify political blogs thusly:

2005 Bad Blog Awards

Worst Right-wing Blog
Worst Left-wing Blog
Worst Center/Libertarian Blog

WTF?

There are certainly more ways than one to divide people along ideological lines, and the differences between the Nolan, Eysenck, Pournelle, Inglehart and Friesian Institute models are instructive, but this is the first time I have ever seen Libertarian and Centrist lumped in together. Is this a common lumping that I've just previously missed?