Is is possible for my machine to get infected simply from browsing to a website?

Today, I went to a site that I had been to many times before.  And all of a sudden, my IE6 crashed and my Yahoo Online Protection came on indicating that it had intercepted a virus.  I don't know if the site is infected or if my machine was already infected and the virus just came alive co-incidentally.

Is it possible that a person's machine can get infected simply from visiting a site?  I was from the old-school thinking that you can only get infected if you explicily run something (like clicking on an exe attachment in an email).  Is that no longer true?  Has the hackers gotten beyond that stage and is able to infect people through their browser?

It is possible when you surf using IE.

There were many vurnrabilities discovered for IE in the pase year. Popups with viruses, images with arbitary code, etc.

yeah, mcafee is also cleaning up viruses from the pounder of adversal if I surf website with IE

Yep, IE is crap!