immediate use...mmm....got a pair of headphones on you?
you could give binaural beats a try. slightly different tonal sounds in either ear to create an audio illusion that works to shift your brain towards certain wavelengths. like ones promoting sleep and dreams (and lucid dreams <3)
http://en.wikipedia.org/wiki/Binaural_beats
http://gnaural.sourceforge.net/GnauralJavaApplet/
--
There is no shame in not knowing; the shame lies in not finding out