Diogodog - definitely know how you feel. Every long run is the'longest I've run in training', and I get terrified before each one. I've started using my mp3 player on long runs again, bought myself some new tunes and made a new playlist, and to be honest last week it was only the thought of that that got me out the door!
As Yvonne said, the thought of a reward is good for motivation as well. I have an enormous hot chocolate after my long runs

hope the run goes well for you today - do let us know how it goes.
Yvonne - shame you're not running it this year, but well done for standing on the 'other'side of the fence this year!
Have been a bit concerned that my shin splints are starting to hurt again, after Friday's not-so-long run. Trying to ignore them and convince myself it's just my imagination trying to invent reasons for me not to have to run. However an sitting with an ice pack on my sins at the moment, just in case.
MadWelshWoman - I feel your pain! Sounds like yours are really sore. Strap running for a week or so to rest them, ice, compression etc but keep up the cardio vascular work with some swimming / cycling if you can. I did aqua running last year, which keeps the same muscles moving as running does but without the strain.
Poohbear and Toby - hope Longleat's going well - looking forward to hearing all about it.
Hope everyone else is well, and any long runs are successful today!