Well, surfing could eat up megabytes quite quickly.. if I read gmail through the browser it takes a megabyte or two, and reading a newspaper online also sucks bytes. If, on the other hand, I read Slashdot through its mobile-optimized version it'll take about 0.5 MB to read a full day of Slashdot. Anyway I'm planning to try a text-based browser (run in an xterm) and see how much data that will transfer (the connection display on the N800 tells how much data is transferred).