gradual pitch/tempo change?

[sshock1]

Hi, i'm new here, please forgive my ignorance.

I'm looking for a free VST plug-in OR a method (to be used in audacity) that will enable me to gradually increase/decrease the tempo of a selection.

For instance: I make very amateur mixtapes in audacity. To mix two beats together, 99.9% of the time requires a tempo alteration, but I don't want my whole mixtape to be at the same tempo... I want to be able to mix 2 beats together, and when the mix is done, gradually raise or lower the song's tempo to the desired BPM.

The only way i know how to do this is to pick a wave section, and gradually, manually adjust the BPM (tempo) of multiple selectoins to desired ascending or descending rates, this however is much too time consuming and sounds like ass.

If you have no clue what i'm talking about, to simplify it i say i want something that mimics the effect of adjusting the pitch on a turntable

any help would be awesome,

thanks