Hi all,
I present to you my humble attempt to compare most used cryptocurrencies. I hope someone will find this useful.

http://bitinfocharts.com/

Coins present:
  Bitcoin
  Litecoin
  Namecoin
  Terracoin
  PPcoin
  Novacoin
  Freicoin
  Feathercoin

Available comparisons:
  Number of unique transactions per day
  Average block size
  Number of unique addresses per day
  Average difficulty per day
  Average hashrate (hash/s) per day

There is also short current info about each of this coins:
  Total coins
  Transactions last 24h
  Transactions avg. per hour   
  Coins sent last 24h
  Coins sent avg. per hour (last 24h)
  Blocks Count
  Blocks last 24h   
  Blocks avg. per hour (last 24h)   
  Difficulty   
  Network Hashrate (avg. yesterday)

Please let me know if you find errors or have any comments / suggestions.