warning: I am not a lawyer and thus not qualified to give legal advice, etc.
I don't know specifically about your situation and the VWP but it's not allowed to do things in the country other than your stated purpose, and other than what your visa allows.
Looks like most normal work is not allowed, except for the last provision there. If you follow to the source, it says "These would-be entrants are not allowed to receive remuneration from a US source (other than an expense allowance or reimbursement) and must be customarily employed by a non-US firm that will continue to pay their salary during the temporary assignment in the US.". So there you have it.
I don't know specifically about your situation and the VWP but it's not allowed to do things in the country other than your stated purpose, and other than what your visa allows.
See: http://en.wikipedia.org/wiki/B_visa#Uses_of_a_B1.2FB2_visa
Looks like most normal work is not allowed, except for the last provision there. If you follow to the source, it says "These would-be entrants are not allowed to receive remuneration from a US source (other than an expense allowance or reimbursement) and must be customarily employed by a non-US firm that will continue to pay their salary during the temporary assignment in the US.". So there you have it.