Although OLPC XO computers and XS school servers are usable without an Internet connection, this is a highly unsatisfactory situation. Current WiMax deployments run about $10 per person for coverage of 90-95% of the population. Getting to the remaining 5-10% requires more expensive point-to-point or satellite links. In areas where satellite bandwidth is reasonably priced (everywhere but some parts of Africa) it is possible to place Internet systems using microfinance, to be paid for out of increased earnings enabled by access to information, markets, and people.
Several countries have let out contracts for nationwide WiMax systems. Private companies are investing in these systems as profit centers for the future in other countries.
It is desirable for countries to add in the $10 or so per person for Internet to the cost of XOs for its children, but OLPC does not bring this up with governments.
Computers and Internet also require local availability of electricity, which can also be provided through microfinance.