is there such thing as a rhythm beater outer thingy?

i frequently come up with rhythms while working things out on guitar, but they are difficult or impossible for me to figure out how to actually notate it. is there anything where i could just tap a button to the rhythm, and have that rhythm displayed on a staff?

You could tap the rhythm into a MIDI instrument and then look at the output in a program like Cubase

Or just slow down your rhythms until they become clearer.

mmh, i was looking for more along the lines of a web app. i don't have MIDI capabilities.