Before I forget: I love black tea when networking. I just do.

• It freshens your breath, quite unlike its darker counterpart. The tannins make the bad guys go away. (This trick only works if you don't have sugar in it). 
• It has lower caffeine than coffee but enough to make your eyes track a little clearer. 
• It's cheap and everywhere.
• You can have it as zero calories and it is uniformly better than tap water in just about every city except Portland.