If so, you probably don't want the word "comparations" but "comparison" since "comparations" means something different that does not seem applicable to what you are doing here.
Looks interesting otherwise. ;-)
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
Avaliable comparations:
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.