I agree with Ian and Bryant regarding using a prefix such as usp_ to define a stored procedure. I always use object type prefixes where there is potential for ambiguity, so for example I would still differentiate Tables and Views (eg tblCustomers or vwCustomers). However a Stored Procedure cannot readily be confused with any other object so the rationale for an object type prefix dissapears.
I also note that Microsoft are moving away from object type prefixes in, for example, the later versions of Visual Studio. But maybe this is because there are now so many objects that a simple prefix is not enough to disambiguate them (with thanks to Ken Getz who introduced me to this 'word' during one of his forays to the UK) 
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Regards,
David Saville
Aldex Software Ltd.