Mondays are rubbish. My first problem of the day is an accessibility one; our developer is saying "drop downs are bad mmm-kay, drop downs are unaccessible mmm-kay, you need left hand navigation mmm-kay". Do you bollocks, you just need to build the site in the right way. Now I'm not a techy, so maybe I'm wrong - I often am - but I'm certain that you can build accessible navigaition and I'm not alone (clicky).
And if you don't believe me switch your CSS off and check out www.diy.com or www.johnlewis.com - mega-drop downs which as far as I can see will work fine with a screen reader.