Dashboard is great and one of the best mac os x features, but if you don't use it why not disable it? specially when it will save resources.

You can do is by:

1) Open Terminal from the Utilites folder.

2) Type:

defaults write com.apple.dashboard mcx-disabled -boolean YES

and press Enter.

3) You need to restart your mac for this to take effect.

here is a video tutorial of this:

see video at youtube