I have a Louis Garneau EcoBox handlebar bag on my 2007 Jamis Aurora. It is roomy but narrow enough to fit neatly without interfering with the interrupter brake levers or the derailleur cables. I bought mine at REI last year but it does not show up in their current online catalog. This is what it looks like:
http://www.gottaridebikes.com/page/GRB/PROD/BAG/BAG0009