Staying enthusiastic about a long term web project

Please share how you keep your enthusiasm going for  a long term web project. When nothing seems to be moving along as fast as I would like, it can be really frustrating.

I have days when I could throw things in the trash that I've worked on for over a year and forget about them completely. What do you do to boost your spirits and revive the spark all over again?

The biggest challenge I face is devoting time to them. When I look at them and it's been a month or more since I did anything, that depresses me.

Any ideas or thoughts would be appreciated. Thanks!