Keeping track of friends and family names and addresses is always tricky and I've never come across an app that really integrates well with my online activities. As far as offline apps fgo however, LS Addressbook does a good job of organizing your contacts in a compact and simple agenda. It has fields for the name, telephone number, address, e-mail and notes, etc.
There are many more options than you'll find in an agenda of a modern mobile phone, but the interesting thing is the export options. It supports TXT formats and XLS so you can export the data for simple backups at anytime or for printing. You can also import data from MS Access if you use it for contacts.
Simple and comprehensive with some useful export options, this is a solid contacts organiser.