Sling Media has announced that its SlingPlayer Mobile client has been released for Palm OS devices. With it and your Slingbox, you will be able to stream and watch TV content on your Palm device. The official version also adds some new features including a battery level indicator and the ability to add all remote control functions supported by the specific A/V device as Favorite shortcuts.
Officially, SlingPlayer Mobile for Palm OS only supports the 3G-capable Treo 755p and 700p, though numerous users are Slinging happy on older devices such as the TX, Treo 750, and Treo 650. If your Palm is listed as unsupported, you should download the 30-day trial and give it a spin to see if it works.