Ad blockers can stop the display of the ad, but it doesn't necessarily solve the horizontal scrolling issue.
At the top of the page I am viewing right now, there is the 125 x 87 flyertalk logo to the left, then a 728 x 90 ad in the middle, then the flash ad on the right margin. Since Mozilla can block non-flash ads, I was able to get a white space where the ad was, but it was a 728 x 90 white space, which meant I still had to scroll horizontally.

(BTW, I changed my screen resolution to 1024 x 768 and the page displayed fine. I hope this isn't one of those situations where the site designers were using 1024 x 768 and assumed everyone else would see the site OK because they saw it OK. 1024 x 768 isn't a good choice for those with less-than-perfect vision and those with small monitors.)