lbzip2 0.23-1 (armhf binary) in ubuntu precise

 lbzip2 is a multi-threaded implementation of bzip2, suited for serial and
 parallel processing. On a multi-core computer, lbzip2 is commonly the fastest
 bzip2 decompressor for most bz2 files found on the internet. (On dual-core
 computers, the 7za utility from the p7zip-full package may prove more
 efficient.)
 .
 lbzip2 integrates nicely with GNU tar. Even on single-core computers, lbzip2
 can speed up archiving in combination with tar, because lbzip2 allows
 compression to overlap with disk usage to a greater extent than bzip2 does.