Many of today's desktop applications are designed for use with a pointing device and keyboard. Someone with a disability, or in a unique environment, may not be able to use one or both of these devices. We have developed an approach for automatically modifying desktop applications to accommodate a variety of input alternatives as well as a demonstration implementation, the Input Adapter Tool (IAT). Our work is differentiated from past work by our focus on input adaptation (such as adapting a paint program to work without a pointing device) rather than output adaptation (such as adapting web pages to work on a cellphone). We present an analysis showing how different common interactive elements and navigation techniques can be adapted to specific input modalities. We also describe IAT, which supports a subset of these adaptations, and illustrate how it adapts different inputs to two applications, a paint program and a form entry program.