The ornamental design for a portablelaptopstand, as shown and described.
FIG. 1 is a side view of a first leg of the portable laptop stand shown separately for clarity of illustration.
FIG. 2 is a side view of a second leg of the portable laptop stand shown separately for clarity of illustration. The second leg is identical to the first, except that the notch in the second leg opposes the notch in the first leg.
FIG. 3 is a perspective view of both legs of the portable laptop stand; and,
FIG. 4 is a perspective view of both legs of the portable laptop stand shown with the legs in a connected position.