One way is with the [tt]net[/tt] command with the [tt]user[/tt] option. Other people may come up with other ideas.
Use [tt]net user /?[/tt] to get the full syntax, but there are two basic options.
If it's a local account, run the command on the NT server (or workstation) using just the [tt]user[/tt] option:
[tt] net user rswift[/tt]
If it's a domain account, run the command from any NT machine in the domain but use the [tt]user /dom[/tt] option:
[tt] net user /dom rwsift[/tt]
Either way, it should output the last logon date (along with full name, group memberships, logon script name etc). You could always | (pipe) the output through a [tt]find[/tt] command to just get the last logon line.