Block IP addresses.

[cd34]

deny from 1.2.3.

will block all from that class C

ErrorDocument 403 http://where/to/send/the/person

will redirect them elsewhere

Many people geotarget - whether it makes good sense is sometimes questionable -- what if a reviewer/linklist owner/tgp owner is in one of your blacklisted countries gets redirected? I think some linklist & tgp owners frown upon it - tread carefully.