Need PS help for portrait background

I had the first portrait session with two nieces couple of weeks ago. I used my 17-40L, 580EX and LSIIPJ at 45 degree bounce. Since I don't have any backdrop, just used the room wall which is light beige. Although the background looks OK (to me), but in a way, it's kind of boring. I tried changing the background color in PS, but didn't get a nice result. I'd like to see the black background and "gel-look-alike" background. So, please show me your PS skills, but also let me know detail step how you did it since I'm a beginner in PS. Thanks in advance.

HOSTED PHOTO
please log in to view hosted photos in full size.

Really quick
Filter/extract take a bit more time than I did and the hair will look better.
Create a new layer, and pic a color that you like and white. (I used the pink in her shirt)
Filter/ render/ clouds
I used the skew in edit/ transform to give the bg a bit of depth.
let me know if ya need help

HOSTED PHOTO
please log in to view hosted photos in full size.

not an exspert but had a go .
i used the magicwand set at 25 tolarance, to get the background, then painted with a light black,then cloned around the hair to blend it in ,with work finshed i gave a bit more saturation ,a little contrast and curves then unsharpmask 05 at 130 .
any better ?
Rob

Wow VERY WELL DONE...have to remember that one...

cheers,

Thanks =) I forgot to mention, blur that clouds layer a bit.

good job learjet i like your effect.
Rob.

I gave it a try too, not as nice as some of the others, but I thought I'd give it a go.

HOSTED PHOTO
please log in to view hosted photos in full size.

Create new path>> use pen tool>> Make selection. BAM!! the pen tool is the most precise tool you can use in PS when it comes to selection

Wow.... Thank you all for spending time. I like them all.

Learjet's edit gave a pop of the subject. As he said, hair could be better, and I understand needing more time to make it better. Other than that, it's excellent!

gyrob's edit made it a classic look. It blends nicely with the subject.

The background on Becca's edit is too dark and gives not much contrast to my niece's black hair. Very nice edit on her face though. I didn't do any touch up except USM.

Again, thank you all. Need to try myself.

Can you do this in PSE 4.0? Thanks.