Looking for retail space... in the rain

My mom always held on to her own superstition that rain brings good luck - at least for our family. She'll state this, and quickly follow it up with a series of examples:

It rained when you were born, it rained when we arrived to this country, it rained when we signed our first lease on a store, it rained when we bought our first home... etc.

So this is what I was consoling myself with as I splashed around Brooklyn's various shopping districts, umbrella in one hand, and my G1 phone flipped open in the other, jotting down phone numbers from empty retail stores.
I've seen several good locations. I've also seen a number of places I like, that are clearly empty, but with no sign. Later internet searches into the unmarked emptys only revealed what used to be there, but not who is leasing the place. It looks like realtors don't list locations by address but by neighborhoods.
Another frustration I have been coming across is that brokers, in a number of areas in Brooklyn, expect the tenant to pay their fee. The fee often being equivalent to 2 months rent. This adds a significant chunk to startup costs, and will figure as a large hole in my business plan figures.
Another factor - that may seem obvious - is that huge fluctuations in rent costs between different streets and neighborhoods. Even within neighborhoods, the difference of just a few blocks can mean several thousands of dollars a month in rents.
My current hope is to be able to use the current economic climate to my advantage, putting pressure on landlords to lower rents, provide better terms, and maybe even take on or split realtor fees.

Having collected several locations, in several neighborhoods, I've now scheduled appointments with several realtors for Monday and Tuesday to look at different spaces.