To explain samoth's post a bit:
The view matrix is the inverse of the camera's world transformation. This is usually a composition of translation and rotation, perhaps a scaling. Assuming column vector matrices, this looks like so:
C := T * R * S
A decomposition of C into a translation T, rotation R, and scaling S, as shown above, is relatively easy. It is even easier if scaling is known to not appear, because then decomposition is just extraction of values.
Then the inverse is
V := C-1 = S-1 * R-1 * T-1