I read this in the Cointelegraph the other day about the Bitcoin core update:-

“Bitcoin Core now uses ‘headers-first synchronization’. This means that we first ask peers for block headers (a total of 27 megabytes, as of December 2014) and validate those. In a second stage, when the headers have been discovered, we download the blocks. However, as we already know about the whole chain in advance, the blocks can be downloaded in parallel from all available peers.” http://cointelegraph.com/news/113498/daily-digest-bter-hacked-bitcoin-core-updated - (3rd article down).

Parallel block downloading - is that something we could use? How could it be done since syncing is a serial process ... isn't it?