Nah, I do that with almost everyone's name tht has reocurring letters or a list of numbers (in your case b, l, and a.) I find it fun. =P
Anyway, if I get what you're saying (not positive i do) then it would not really be a "touch pad" but more of a strange variation of an analog stick. To me, doing someting like that would only be useful in making the machine look "cooler" without enhancing the gameplay and still making it harder to control. (what I think happened with the concept design for the PSP. The control pad looks cool, but if you think about it it would make any agme difficult to control, both 2D and 3D).
Of course, I kinda drifted this from a "touch screen" to a "touch pad." You wouldn't use a touch screen to control, but to just "click" on things (ie buttons on an in game cell phone, like a PDA.)