Milk Guitar is a strummable, MIDI-controlled virtual instrument which you can use with any multi-track vst-compatible host.
It contains a few well-sampled chords that are easy to play and and strum using your midi keyboard. It has several built-in effects including room and reverb controls, harmonics, bass cut filter, and the super-sweet stereo widening effect. Pre-defined combinations and strumming keys allow you to strum and tap with ease. And because it's midi, it's very easy to quantize your guitar part.