Recruiting has become the most sought after skill among founders and one of the things companies look for as extra value a VC can bring.
Not sure there is a good way poach, aside from being a good sport and not rubbing it in. That and following through on the promises you make (looking at you Zynga).
If someone else can offer one of my guys a better deal than what I can (and by deal I don't just mean money), then I send them off with my good wishes.
I realise this comes across as naive, and I certainly don't want to minimize the huge disruption someone leaving a busy small team can cause, but if you start seeing people as property and laying your ego on the line every time you have turnover, you are going to have a miserable life.
[Disclaimer: I don't work in startups but I do work somewhere where it typically takes 9 months to re-hire, so don't think I don't feel the pain]
Not sure there is a good way poach, aside from being a good sport and not rubbing it in. That and following through on the promises you make (looking at you Zynga).