Samsung has introduced two new portable XM receivers, the Nexus and the Helix. Both are hard drive based devices which support MP3 and WMA audio tracks. Additionally, they both allow you to record XM content for later playback. Like the Sirius S50, the Nexus is limited to playing live satellite while docked. However, the full-color Helix has a built-in antenna for live XM on the go. The Nexus comes in $199 and $299 sizes; the Helix is $399.