I would second deefer dog's post. However...
Visit the places where biz jets hang out, find out who operates what and write and get to meet the crews. It isn't something that takes 5 mins to achieve, but if you want it hard enough you will keep going until an opportunity comes along.....then it's simply a case of grabbing it with both hands.
This can be a difficult task if you are not already airside. Many small airports (where bizjets from entry level to top notch hang out) have very tight security in place (i.e. Biggin Hill) so it might be difficult to get any closer than the car-park.
Having said that, I got my first King Air job while instructing. Needless to say that day it was solid IMC, thus nothing better to do than chat up a transiting bizjet's crew...
Good luck
DK
