It's been a rough week at work.  We have a lot of projects that are due.  I've had to bring work home each night this week so essentially I'm putting in 12-13 hour days.  I don't mind much but will be happy when things slow a bit so we can catch our breath before the next onslaught.  I've got skills that allow me to help people in other departments and I rarely, if ever, say no to requests for help.  I'd rather bust my butt to help out so that the documents going out are the best they can be.  However, this week, I had to say no to a few people because my work is backed up.  I gave them other avenues to get the assistance they needed.  But, no, that wasn't good enough.  Each of these people decided to try and nag or guilt me into it. 

"Well, will it really take you THAT long?"
"I know you are very busy with your deadlines but I hope that you will help me anyway"
"But I'm in the middle of a project and need this!  I'm going out for awhile - won't that give you time to find what I need and get it for me?" 

It really doesn't want to make me do favors anymore.