[Bioperl-l] how to get annotations (especially ensembl IDs) for a list of genes?

[zhihua li]

Hi all,

I have a list of like 300 genes (actually their refseq IDs).  Now I wanna 
get more information (annotations) for each of the genes. Speficially, I 
want a mapping of the refseq IDs to Ensembl gene IDs.

I know how to do it through a web page. But I'm wondering if I can also do 
it via bioperl, by using some modules or packages. Can anyone help me out 
here?

Thanks a lot!