I had some output that was really difficult to read and so I wanted to split the output into blocks that were similar - where they had the same $1 value. This fab little awk command puts a blank line between each block (multiple lines) where $1 changes.
(don't ask me how it works tho because I got it off a really nice chap at www.unix.com)
awk 'x[$1]++||$0=NR==1?$0:RS $0' test2
If anyone can explain it to me please feel free! :)