[BiO BB] API for gene ontology retrieval?

[Ahmed Moustafa]

Hi All,
Is there some API or an automated method to retrieve the annotation 
(gene ontology?) of a set of sequences?
I believe BLAST is necessary but after BLASTing the sequences, how can I 
get the annotations (e.g. cellular component, pathway, biological 
function...) of (for example) the best hit for each sequence?
Your help will be appreciated so much!
Thanks in advance,
Ahmed