Bowstaff

This thin, flexible quarterstaff has a bulge in the center and tapered tips.

By activating a bowstaff, you can change this +1/masterwork quarterstaff into a +1 longbow or back again. Each version performs like a regular magic weapon of its kind.

Prerequisites: Craft Magic Arms and Armor, polymorph any object.

Cost to Create: 2,000 gp (plus 600 gp for masterwork quarterstaff), 160 XP, 4 days.

Source: Magic Item Compendium, page 48. Originally published in Complete Adventurer, page 129, as a more expensive +2 quarterstaff and +2 longbow.