playing electric string instruments directly into score

Has anyone yet thought of an affordable way of using an electric string instrument for what an electric keyboard generally does best - namely putting in notes on a stave/in a score, so as to produce notes on a stave/in a score? Some interface/USB-to-MIDI solution will be necessary, I suppose - but everything I tried, so far, has failed miserably. Morover, this subject has been bugging me for the last 5 years, so I'm in real need of fresh ideas.

What else I'd like to see - in combination with the above - is something along the lines of Flexi-input (like in big brother Sibelius), which allows playing directly into the score. This may also come in useful, in my experience, for "borrowing" certain musical instruments for recording purposes.

Petbon