what i would suggest do is on the server itself, create a VIEW that selects the data from the trace; the view would run under the context of the owner of the view, right? then I believe you can easily grant SELECT permissions to a role or user. does that sound right?
something like this, which is selecting my default trace files from a default SQL 2008 installation:
CREATE VIEW vw_LookitMyTrace
AS
SELECT * FROM ::fn_trace_gettable('C:\Program Files\Microsoft SQL Server\MSSQL10.MSSQLSERVER\MSSQL\Log\log_10.trc', default)
Lowell