Visit the R.I.P.E. database in order to get the list of all Ip-range in use in Europe :

http://www.ripe.net/ripencc/mem-services/general/allocs4.html

RipeIpAddressAllocations.zip (155kb)

For Asia, visit APNIC site :

http://www.apnic.net/

http://ftp.apnic.net/stats/apnic/

For America, visit LACNIC and ARIN sites :

http://lacnic.net/en/index.html

ftp://ftp.arin.net/pub/stats/arin/