At my last interview I asked why they wanted to know (cheeky).They said it was just so they know if there are any time constraints under which they must get an offer to you.Secondly, the companies you apply to indicate your genuine career interests - if you are applying to a wide range of positions then that shows poor focus. I demonstrated through my applications where my interests lay.If you're decent you should have your finger in a few pies, looking to pull out the nicest plum - remember you have the power!!!! Don't let the b**t**ds hold you over a barrel.