[derf_]

> but information is one of the only things that is free to transport over planets

The marginal cost in terms of power may be very small (compared to a rocket), but the infrastructure costs are enormous, and as a result you're severely capacity-constrained.

Current link to Mars Odyssey from DSS 35 in Canberra is 14.22 kbps (roughly equivalent to a modem from 1991).

[dvdfvo]

Satellites are very cheap compared to manned missions. Speed will not be a problem then.