Finds all empty JPEGs at current directory:

find . -maxdepth 1 -name "*.jpg" -size 0

Finds and deletes all empty JPEGs at current directory:

find . -maxdepth 1 -name "*.jpg" -size 0 -delete

Finds and deletes all empty JPEGs in all sub-directories.

find . -maxdepth 2 -name "*.jpg" -size 0 -delete

Sources: 1, 2

Looking Projectwide for NSLog's:

Shift-Apple-F: [^//]NSLog

All the NSLogs, which don't have // infront of them.

Update: This might be a more elegant way to get rid of the NSLogs. 447