The smallest portable Sirius satellite receiver buffers 44 minutes of music or talk, so you can replay something you just heard. But if you enjoy channel surfing, be warned: The buffer clears the moment you change channels (or if the unit loses power).

The Sportster Replay has all the usual bells and whistles, including channel presets, an FM modulator, and an optional home kit. It is twice as large as the Delphi/XM Roady devices, but Sirius has the edge on sports programming; fans will like the team logos at startup and updated text sports scores. A Sportster without the replay ability is $80.

Sirius' ability to engineer truly tiny products hasn't yet caught up to XM's Delphi. In a larger vehicle it won't be as noticeable, or if you secure the cradle to the vertical face of the dash and leave off the largish swivel-mount stand . Just be sure you don't mount a portable satellite radio receiver where it would be deployed along with the airbag and give literal meaning to the phrase, "I can't get that song out of my mind."