I'm assuming that your ipod
is an ipod touch
, as that's the only one I know of that lets you make entries in the calendar.
I'm also assuming that you have a Mac; I'm sure this is possible on windows (both iTunes and Google Sync will sync with Outlook), but I'm not familiar with how to do it.
Start by configuring iTunes to sync your iPod calendar and the iCal on your Mac; this will give you an option to pull from your iPod onto your Mac.
Next, use Spanning Sync or GooSync to synchronize your iCal with your Google Calendar. Either of these will let you bind your local calendar to your Google Calendar, and push the events from your iCal up to the gCal
Alternately, it may be possible in iCal to just set up the Google Syncing and then mass-copy all your events to that calendar - I'm not sure.
Once you've done this, you've successfully pulled everything that used to live on your iPod into the cloud. At this point, you could have your iPod sync directly with the cloud; or you could leave it the way it is: iPod syncs to iCal which syncs to gCal. You can accomplish the latter with one of the sync products, or just use the native CalDav sync.