Project Gunrunner-Bush
Fast and Furious-holder/obama
Gunwalker-nickname given to F&F by David Codrea and Mike Vanderboegh who broke the story.
I think the ATF may have beat them to it although they aren't using the term 'gunwalker' as a noun.
The Department of Justices Operation Fast and Furious: Accounts of (four) ATF Agents
In that House Oversight Committee Report four ATF agents repeatedly use the terms 'gunwalking' as verbs to describe what they were doing. There is even a chapter titled "V. Gunwalking Defined: Its Semantics"