I get pretty close to the bees. I don't have the budget to buy a Nikkor 200MM AF Micro lens to keep my distance. So I have no choice but to get close. Often I get 1/2 an inch to 2 inches away from them. In doing so, I also keep better track of their movement. Bees are fast, and for every flying picture you see I probably took 100-200 pictures that didn't turn out. Last summer I took over 700 pictures over one particular weekend, and only three flying pictures were publish worthy.
The equipment I use is a secret (sort of). All I can say is that I use a DSLR, along with a lens attached to an extension tube, both of which most people sell for peanuts.