My basic aim is to launch an activity from within another, and have
the result of the second activity be returned to the first. Problem
is, the second one keeps crashing. LogCat reveals that there was a
NullPointerException at the first after the second activity was
finished. Do I have to apply certain intent filters to it, or put some
other attribute in the manifest? Am using the onActivityResult method
in the first activity, and just and using



in the second activity, where sLat and sLon are strings.

Help would be appreciated. Thanks.

Could you please try to debug the code and get the actual location of the code where the Null Pointer Exception is occurring. You can debug the project or even you can use the System.out.println's. Try to print the values which are required to move to the first activity.

This is another, same discussion going on and it can be of any help for you.
http://www.anddev.org/other-coding-problems-f5/back-from-activity-problem-t51677.html