The ornamental design for a hand-held computer, as shown and described.
FIG. 1 is a front elevational view of a hand-held computer;
FIG. 2 is a left side elevational view thereof, the right side view being a mirror image thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a top plan view thereof; and,
FIG. 5 is a bottom plan view thereof.
The broken lines immediately adjacent the shaded areas represent the bounds of the claim and all other broken lines are for illustrative purposes only. None of the broken lines form a part of the claimed design.