It's in Beta stage at the moment, and is only available for web/software developers, although you could probably get it from somewhere if you typed in "Internet Explorer 7 download" into google.
I believe it's officially sheduled for release in the summer for Windows XP SP2, but will also come with Windows Vista.
also bear in mind that firefox isnt really any 'safer' than internet explorer, its just that while the majority of us still use internet explorer the creater of viruses, trojans, spyware etc will target the bigger audience.
I have to add that I disagree with PatTheRat. There is that perceived element of security due to Firefox not being as widely used (yet) as IE but it is not the only reason for it being more secure.
Anyway, as bobjim said, IE 7 is still in beta and is only available to MSDN subscribers. Even if you do get hold of it, I would not recommend installing it on a machine that you use (ie, a home machine, your work machine). There is a reason it is still in beta!
Ok guys, point taken. I have a friend who is a programmer and he has stated that it is just as easy to write a code to manipulate firefox as it is to do so to IE.
With no programming skills, I was taking his word for it.
Pat: he's correct. it is just as easy to write something. but there are less security loop holes in the first place, and when they are found, they get fast a lot faster, as anyone can fix them, not just some guys in Redmond.