Whether to accept trips etc. is variable in my book.
I both accept sometimes and turn people down sometimes.
It depends on the relationship I have with the program, and how I get along with the manager. If I expect great pressure I am not interested in getting freebies.
As far as going to conferences goes, I have started to prefer paying my own way for a number of reasons – one being that I like to attach vacations to them, another that I like to be free to spend my time anyway I like and talk to any program I like. If you let people pay for you they may get posessive and demanding. Like I said, it depends on my relationship with the program.
“Outings” are another story. Whether small outings during conferences or fulfledged vacations – they are sponsored exclusively by one program that is working with you already and I like these and do usually accept.
Accepting a freebie from a program you don’t like to advertise or that doesn’t convert for you is something to be done with caution. You may both end up unhappy. I don’t do it anymore.