I've been giving this thing a workout lately to 're-amp' some hard sounding digital tracks:
http://www.tapeop.com/magazine/bonus/dbx386.html
Don't forget besides tape a good sounding tape machine has transistors or tubes and maybe even a transformer (?) so there's lots of stuff to color the sound. Getting a broken transport that has working tubes is a fun thing I've been thinking about doing and just using the pre-amp.
Somebody mentioned PSP Vintage Warmer that's got the computer simulated saturation.
Ruby tube (VST) is free I think that's a fun thing to toy around with:
http://www.orion-central.com/reviewrubytube.shtml
I just got the Warmtone (DX) I think has a demo:
http://www.aipl.com/warmtone.html
Endorphin has some saturation on it:
http://www.orion-central.com/reviewendorphin.shtml
You got tube and tape saturation, I think there's a type of transistor that has a good sounding non-linear zone (FET, I guess ?) - I don't understand transformer saturation yet (couldn't recognize it). Then there's that non-linear opto thing some compressors have that's cool too - I think
digitalfishphones Blockfish compressor (VST) has the opto curve.
I'm starting to think that my computer based saturation plugins need a pretty well balanced mix so you don't push into them as hard as an analog outboard piece. Pushing individual tracks into computer saturation is probably a different story...
Davedrummer -
I think the comment you made about a DSP chip that 'simulates' tape saturation will be mostly just a simulation. Not to say it won't sound good in other respects but by definition it will be different. Wouldn't it be a kick if you opened one up and there was a little tape loop in there ! Ha Ha

Now I'm thinking that Space Echo I've got sittin across the room might be good for some fun, hmmm...
Here's to [good sounding] tape saturation !
kylen