In addition to the previously noted changes due to climate and normal geology, the sudden removal of humans a la Discovery Channel's Life After People would quickly lead to the breakdown of electrical and mechanical infrastructure, including pumping stations (e.g., the California Aqueduct, New Orleans' pumping stations, and the Netherlands' pumping stations in Flevoland), with the obvious results. In the longer term (a few centuries at most, according to Discovery), the majority of earthen and concrete structures are likely to fail, which includes essentially all of the world's dams, dikes, and levees. Their collapses will cause significant flooding, erosion, and scouring of low-lying areas downstream, and some river channels will be changed significantly enough to still show the effects a millennium hence.
Earth's cities and highways are also likely to be largely buried in vegetation (again, per Discovery), with the result that urban and linear features that are prominent from the air or even space will become much harder to see.
The disappearance of humans will also eliminate agriculture and logging, which is likely to reduce silt and fertilizer runoff in most places, with at least some visible changes in watersheds. (For example, mangroves can be expected to make a larger comeback in some rivers; clear-cut areas of the Amazon and other forests will recover to some extent; and a number of river deltas like the Ebro's will stop growing so quickly and may actually erode.) The Aral Sea may make a comeback as well.
Astronomy might also play a small part; according to Wikipedia, there's about a 20% chance of an asteroid strike large enough to create a crater actually hitting land and doing so.
By the way, spacecraft, even the ISS, are too small to make much of a mark, and what little damage they do cause would be hidden by vegetation and weathering very quickly (years, or decades at most).