LatifyLite is the free ad-supported version of Latify for Google Latitude. Latify is a Google Latitude client giving you fine-grained control over how your locations should be uploaded to Google Latitude and is optimized to be very battery efficient.
It puts you in the driving seat on how frequent you want your location to be updated.

Revisit your location history using the interactive map viewer. Decide for yourself how frequent the phone should process your locations.

All of this in a very battery-friendly way

Value-added services include :

Fine grained location polling
Background location reporting
Location history visualization
Offline mode / delayed Google Latitude sync (Premium version)
Share and record your trips with others (Premium version)
Fusion tables viewer
Battery efficiency
Fusion Tables support
Live location tracking

Please be aware that continued use of GPS running in the background can dramatically decrease battery life. This is the case when your location will be updated using GPS at a high frequency (fully configurable through the location polling profiles).