This is the first vectored wall I'm making,so please help me!
I don't have a bloody idea what to put in the background...and I'm still wandering should this wall be a daily or a nightly one...
Any advice appreciated

Here's the wall

http://img516.imageshack.us/my.php?image=vectorwall2al7.jpg

Amazing vector! It looks so well done.
As for the background, I would go for a daytime sky, since the wall looks so bright.
Some painted clouds might look nice.

I'm agree with Naomi-chan, daytime sky will look great but you can experiment with a sunrise blending blues and some pinks for give warm to the whole image.

Btw the vector is awesome! ^^ Nice

very nice vector chris! it's very good I like the texture on his clothes about the background I agree about the daytime, maybe some extra details like birds or something like that

Agree with all the others here but maybe you want to check on the outlines of his hair once more because they look kind of jagged.
Good luck to you.

i think you should add some green in the picture, and a dark blue sky, but anyway its a nice vector (already downloadet it)

very nice how long did that take you. I noticed a bit of white outside of the line of the building behind him, don tknow if that was intentional. Oh and his hair in front does have one or 2 transparant ends. (and theres a little bit of white between his 2nd-top hair and the background)
still very nice vector, good job on the eyes.