Argh! This question is distracting me from my work.. see what you have done :D

I agree with the others: find ways to enjoy what you do hr by hr.

Part of my day job involves analysing up to 1,000,000 images at a time and categorising them (that many images takes around 3hrs with our software). That gets VERY boring: what I do is set myself targbets - so I say "at 40,000 I will read my mail". Only when I get there I say - oh just another 5,0000. I developed a very usfel OCD-like thing of not beign able to stop until the "done" number reaches a precisely round number (which nevert happens :D) like 10,000 etc. :)

Try something similar: set short targets after which you will break - but then extend them. Set targets and what time you hope to reach them by; but make sure you will easily make it in the time you set. Then say "oh well in the time I have left I could do... xyz".

Keep setting tiny targets till you can't face it anymore and then lose yourself in the net for a bit :) (until you realise you should be back at work).

I have found that forcing work in this way for 2hrs then breakign for 20mins gets a lot more work done :D