"delete as appropriate"?
Smartphone? Nah, much smarter to carry something smaller and more comfortable (same comment applies to other larger "phones").
Mobile computer? That's my macbook and it's various peers. Or even the compaq behemoth complete with CRT screen my then-colleague used to lug around in the boot of his car in the 1980s.
No, the N900 is a pocket-puter. Something to take places where the macbook would be a liability. From cycling or backpacking, through to an event like FOSDEM where power outlets and sometimes even seats are at a premium.