I used to use Cool Edit Pro, but now I exclusively use MixMeister Pro. It does everything I want in a mixing program - catalogues and BPM-counts all my collection, does mixing and alignment graphically, allows you to set 'midpoints' that align to the beat, the speed-up and slow-down is acheived without pitch shifting and no audible quality loss, you can add DirectX effects to tracks and to the entire mix, it burns to CD and broadcasts via WMA... what's not to like? I can wholeheartedly recommend it. Try some today! :-)

The pitch matching is acheived mainly by choosing the right songs to mix together - if you're constrained to play certain songs then it's going to be much more difficult. In MixMeister I've had success with changing the playback speed of the master track, which does change pitch, and then using its non-pitch-altering speed adjustment to get the beats aligned. I used to use CEP's time stretching (didn't affect pitch but 'blurred' the music), and then went to pitch shifting, to make things aligned. MixMeister solves these problems, and as noted there are DirectX plugins (costing money) that do seamless, harmonically correct (i.e. no chipmunks) pitch shifting.

Keep in mind that the ear is very sensitive to pitch and to two beats being out of phase, but it's much less sensitive to actual speed of track. See if you can hear the BPM change in the track "Radio Jordan" by Josh Abrahams in the Laidoutback mix. It goes from 104BPM to 120BPM in a sliding pitch shift over about two minutes - it's almost impossible to tell that the track is that much faster, but it's easier to tell (e.g. by humming) that it's higher pitched... As you've discovered, spreading this around makes mixing a fair bit easier. (But keep in mind the logarithmic relationship between speed and pitch - two tracks 'glided' at the same rate may still have lots of problems synchronising.)

As for the legality, I don't know. I take the attitude that I am not trying to pass off work that is someone else's as my own, nor am I trying to make a profit off this - at least not much of one :-) (After all, you can still download the mix for free, it's really just my time and materials for the CD burning and printing that I'm covering). And most semi-pro DJs have mix tapes or CDs that they have at specialist music stores to promote themselves, so that people can get a feel for what the DJ does. I buy a fair bit of music (though I'd like to buy more :-) and I want to support the artists, which is why I buy from specialist CD stores or the labels directly. While I think that the recording industry is an example of capitalism gone horribly wrong - why does someone that has nothing to do with music and has little or no ability at creating it get most of the profit from the sale of music? - I'm not using my mixes in a fight against The Men.

Sorry about the long answer - does that answer the question thoroughly? :-)

Have fun,

Paul

P.S. Sure, send me a link to a mix; I'll give comments just as fairly as I receive them. (And I do have a wide taste in music... within certain happy limits.)