latest weird free software setups to fool around with:

try this:

download and install all of these(all these are free btw):
silent bob
(enables you to record any sound that's coming out of your soundcard and save to .wav, you'll need to spend maybe $10 on some other equipment to fool around fully... more on equip later)
ots cd scratch 1200
(a cd player that you can use to scratch cds with the whole authentic vinyl effect... very good at that... no ability to record what you make though, and that's what the above is for)
analogx scratch
(enables you to scratch and save .wav files)
bon wav2mp3 converter
(enables you to convert .wav files to .mp3 files to save space)

can't really save with the above, but if you wanna play around with more:
kb piano
(enables you play with your keyboard as a piano keyboard)

getting any ideas by now?

for equip, just go to radio shack and get:
a 1/8" stereo to 1/8" stereo miniplug... that enables you to plug the line in from your soundcard to your line out of your soundcard
and get a headphone adapter, which branches your line out to 2 outputs... this enables you to be able to still hear what you're doing, as you're gonna plug the above into the line out part

i'll leave it to your creativity to figure out what you wanna do from there...

some other stuff that might interest you:

beat it- like linkin park's keyboard; load up to 16 samples, and you can play them back
ap guitar tuner- best software tuner... ever...
hammerhead rhythm station: still my fave music ap... next to any recording software such as cakewalk's music creator... make authentic drum loops, and then save them as .wav's...

of course, dj'ing's not my main... guitar playing is... but sometimes it is interesting what happens when you combine scratches and dist w/emceeing aka linkin park