All the Tablet bloggers are pitching in ideas for Microsoft's internal Power Toys competition (it's so easy to think of software). Loren's suggested a "snap on dwell" tool and Peter a "pen scrolling tool." So my suggestion is that if you can't pull off a fully customizable and skinnable tablet input panel (which, by the way, ought to have pen-friendly keyshapes):
...and you hate radial context menus...
... then can't you at least see that we need an IE toolbar with an ink-enabled address combobox?