Phil quoting me has directed my attention back to this thread and despite the great advice being given, it seems to have taken a nasty turn somewhere along the line which I still can't fathom. Gothgirl, I think your decision to invest in a separate flash unit is a sound one, and will enable you to be much more creative with your lighting. That said it was a while before I invested in a separate flash unit and tried to make do with what I had. I took a look through some of my earlier experiments and found this one which might help to illustrate the point (I believe someone was asking for examples);
This was taken using the pop up flash with the cardboard roll left over from a roll of toilet paper on top to direct the light to the right hand corner of the room. Admittedly it is rubbish, but there is some directional light going on. Also this was in a white bathroom with the duck placed on the edge of the bath, so the light was bouncing all over the place, but it honestly looked far better than having the pop-up flash pointed directly at the subject.
I also found this example of a similar setup that was taken shortly after I got my first flash (I went with the 430 EXII, but my next flash purchase will likely be a yongnuo):
Again this is bounced light (from above I believe) and I would describe it as even, but boring. Again this was taken with the flash on camera, but obviously I have more power to play with.
It wasn't until I started playing with off camera flash that things started to become more interesting (ok the lighting at least if not the subject matter):
Sorry I don't have any examples with black backgrounds, but I might give it a try sometime if I get the opportunity. While I do think these are good comparisons of the differences between pop-up and separate flash, I don't think they help you much with your particular issue and I suspect you will still need to figure out a way of moving the snake away from the background in someway (or possibly try with felt, as has been suggested), even if you are able to be more creative with the lighting.