No more space...

Hi,
for some time now, I've been exceeding the capacity of my iPod Touch. I gradually had to remove media, until now I only have apps and music, as you can see.
While I understand that 16GB might be insufficient for me now, is the 4.42GB allocation for the apps normal? I have an app which stores a local dump of Wikipedia, which measures ~2GB, but I'm not really sure where the rest could come from. Is there any way of inspecting the contents of the app data?
Otherwise, I guess my only solution is to start deleting apps, which is a shame since the apps are the reason I love my iPod touch. Or I could start lugging around my old iPod simultaneously, which ultimately defeats the purpose of the iPod touch as an all-in-one media device...