Is there a way of combining two or more small UV maps into one larger map? I seem to recall that there was a function in 2.4x that did this (I think it was called consolidate UV's or similar) Making everything you want into one object, unwrapping and then separating everything again seems a long winded way of doing things.
Ensure UV Maps are named the same prior to merge (unless you want the UV Maps to remain separate) then combine using CTRL + J.
To combine the UVs you just need to combine the objects.
In order to combine the objects, select both objects and press CTRL+J. Which ever object is active will be used as the final object, merging the first one into it.
Upon combining the objects the UVs will also be combined, allowing you to organize as you wish without needing to re-unwrap the UVs.