The ornamental design for the portable holder, as shown and described.
FIG. 1 is a perspective view of the present invention, where the dashed lines indicate that the top portion of the article can have any shape that has a width greater than the bottom portion of the article shown in solid lines.
FIG. 2 is front elevational view of the article of FIG. 1.
FIG. 3 is a side view of the article of FIG. 1.
FIG. 4 is a top view of the article of FIG. 1; and,
FIG. 5 is a bottom view of the article of FIG. 1.
The dashed broken lines in the figures illustrate portions of the portable holder that form no part of the claimed design.
The article as described is a portable holder for cups, bottles, and the like that can be hung on a vertical structure, such as a fence or wall.