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I've got a bussed resistor:

enter image description here

The package I'm using has 13 inputs and 1 output, tied to ground. I'm only using 11 of the inputs. Do I need to worry about the floating end of the two unused inputs? Should I tie them to ground?

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What are you using the resistor network for? Is it just a bank of pull-ups? For the most part, leaving the unused ones unconnected is okay. – Nick Alexeev Jul 22 '14 at 18:24
If you're going to connect them to anything, connect them to the same thing pin 1 is connected to. Then you don't draw unnecessary current. – The Photon Jul 22 '14 at 19:14

Leave them disconnected. If you connect them to ground, and your input is >0V (with respect to ground), you will be creating unnecessary current draw in your circuit.

Note that this is different from having unused pins on a microcontroller, where you might tie them to ground (or Vcc, depending on configuration) to prevent undesirable side-effects when reading values from an ADC, getting random resets on a reset pin, etc.

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Not only should you leave them open, leaving them open allows you to use them to fix oversights and problems during bring up of the board i.e. blue wire. Perhaps put a pad or connection to them if you want to (not absolutely necessary).

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