When a disabled employee requests accommodation to help him or her perform the job's essential functions, don't just knock the ball back into the employee's court by saying, "What do you want us to do?" It's up to you to actively help look for solutions.
Courts and the EEOC have made clear that the process is an interactive one. By delaying the process, you invite a lawsuit.
Start by looking at the claimed disability and the restrictions that go with it. Then pull out the job description. Can you eliminate some unessential job functions? Are there essential functions that can be modified to fit the employee's restrictions? Go over the job description with the employee and brainstorm ideas. If none comes to mind, do some research on adaptive devices and services. Only after you've made a good-faith effort to arrive at an accommodation (and thoroughly documented it) should you deny an accommodation request.
Recent case: Hospital stock clerk Arnie Armstrong hurt his back and had trouble doing his job. His biggest problem was transporting sheets and towels using a cart. He asked for an accommodation but never suggested any particular one.
ignored his request, believing Armstrong simply didn't want to do the linen run. He filed an ADA suit, alleging failure to accommodate. The hospital argued that it didn't need to suggest any accommodation ideas until Armstrong came up with his own ideas. The court rejected that idea and sent the case to trial. (Armstrong v. Burdette Tomlin Memorial Hospital, No 03-3553, 3rd Cir., 2006)