for me, a large part of the richness and usefulness of the n900 is being able to go online. i have an unlimited 3g data plan for about 30usd a month.

if you don't have 3g, at least consider using wifi for connectivity. however, you are tied down to a limited cover area which means some use cases are off limits (ike gps navigation unless you get something that has the maps loaded locally like sygic or caches the maps).