"apt-p2p is a p2p proxy for apt dowloads, it will act
as a proxy between apt requests and a repository server,
downloading any request files from peers (if possible), else will
fallback to direct HTTP download. In general, apt-p2p save
bandwidth, use limited cpu and memory resources and reduce
congestion on the ubuntu mirrors.apt-p2p will get the request files
from peers, therefore, it will avoid the congestion on the ubuntu
mirrors.
"Note:- This is only for advanced users this might break your
system
Note: This is still a beta release. Do not install it on production
machines. The final stable version will be released in 23rd April
2009."