LXR is a lightweight tool that lets you insert small amounts of delay to each channel of a stereo track. It can be useful for widening vocals, instruments, and even entire mixes. It can also be useful for creating drone and chorus effects.
Channel delay, as simple as it sounds, can work wonders in your mix. A 10ms delay in the left or right channel can make your track sound a bit wider. In my experience it can even create the effect of taming harsh low frequencies and sibilants.