Hi SilverTurtle,
Difficult question.- For two weeks now I've tried to find an answer to this question by surfing through all "Greek-related" pages. (But sometimes I just get more confused

)
Some similiarities:
- We start being member of a fraternity at university, but we stay member as long as we live.
- Other members are called brothers and sisters.
- There are fraternities, co-ed fraternities and sororities.
- We decide between three stages: 1. Fux (~pledge), 2. Bursche (fully qualified member) and 3. Alter Herr/Alte Dame (~alumni)
- We have our special signs, needles etc.
- People say we do "hazing" (is that the right word?) and that we drink too much

Some differences:
- Some of our fraternities fight with a sword ("Mensur")- I've never heard that from an American fraternity.
- We don't get any help from the university.
- Charity work is done only by a few fraternities.
- Instead of Greek we use plenty of Latin names and words.
Do you have nicknames in your fraternities? We all have so-called beer-names which are always used when we speak with our and other fraternity members. It's a result of the times when fraternities were forbidden in Germany. My beer-name is Veritas.
Regards and our Latin salute: Vivat, crescat, floreat!
Veritas Z!