While stock installations of Android only have 5 home screens, there can be a fair amount of swipping to move from the furthest left screen to the furthest right screen. The other day I accidentally discovered a feature that displays all of the home screens as thumbnails that you can tap to open. It turns out that while I made the discovery after installing Android 2.2 on my Nexus One, the feature has been on it since it shipped with Android 2.1.
To see a thumbnail overview of all the home screens, tap and hold on the app launcher button. You can also display the overview if you tap and hold the dots on the left and right bottom of the screen. The dots indicate how many screens are available to the lefr or right of the current screen. To switch to a home screen, tap the thumbnail of the screen in the overview.