Hey, I am a double bassist, but my jazz band teacher asked me to do some slap electric bass for a funk song. Thats not the problem I've generally figured out the basics.

My problem is me and the guitarist want to do a trade off solo where either he does a measure or two then I do a measure or two. Like a call and response solo, or we might do sections where he does a solo that leads into my solo. My problem is now I am up to create a funky bass solo over 8-10 measures of D7. I have two days until I have to show something, and 3 months till i have to have a final finished solo pretty much, but the sooner the better. For now I was planning on simply playing a blues scale type deal. But any hints?

i always write my solos down...than play them, than change any notes i dont like. thats just how i roll though..

Pretty much go by feel.
Think of something in your head and then try to do it on bass. Usually it will come out different, but hopefully this will improve it. Play around with it a bit (or a lot) if necessary until you have something you like.
If you're doing a call response type thing t might help to think of your bassline as a person saying (or singing) a passage that can be responded to ..... I hope you understand what I'm trying to say here ...
Anyway I'm no expert at funk .... especially slap ... but usually when I want something it happens in my head first then comes out of the bass second.

If you're playing over D7, forget the blues scales and hit up the Mixolydian mode, baby!

Well, I'll assuming you are playing in 4/4...
Use the technique open-hammer-pluck and play the following arpeggios
E-E-A-A-E-E-D-D-E-E-A-A-E-A-G-E

Basically, for the E arpeggio, which is pretty much a E power chord, but anyway... hit your open A string, hammer on 7th fret on the A string, pluck open G string, hit your open D string, hammer on 9th fret on the D string, and pluck the 9th fret on your G string... Same goes for A except you shift up a few frets... etc, etc. It should sound something like a banjo roll.

Here's a clip of something I played a long time ago, using that technique. (the beginning's just crap, what I talked about comes in at 0:09)
http://www.youtube.com/watch?v=dyE503mUncw

i just slap with hammer-ons and pull-offs in any pentatonic when i feel like doing a "funky solo". i call it cheating

Don't play too many notes. If you really want it funky, just do a groove with some tasty little fills thrown in.

fonky thangs:
first and foremost - groove
others
#9 to M3
6th(13th) to m7
b5, 4, m3
M3 to b9
using approach notes