Listen to Beast. That's good advice.
I'll add my $.02, tho (heaven forbid I leave a concise post!)
I'm a 1L and I use Macs exclusively. And I'm not alone - I'd guesstimate that ~ 1/3 of my classmates are using Macs. My school (Michigan) has been great with Mac support, and we can use our Macs for exams as long as we have the new generation (duo core Intel processors instead of Power PC processors) with Windows XP loaded. In other words, those of us with Powerbooks or iBooks had to replace them with Macbook Pros or Macbooks.
A great resource is http://www.maclawstudents.com
. Erik has great information posted about a lot of different schools and their openness to Macs. And let me know if you have any questions.