My ideal commuter bag is my backpack because I usually have a pretty light load and don't have to dress fancy for work (edit: I also like to bunnyhop and otherwise unweight my rear wheel from time to time and crap on the bike proves a great hindrance to those activities). I still take the bike with rack and panniers occasionally, though.
Originally Posted by
That Linux Guy
Also, what kind of question is that? What commuter bag can you strap directly to the frame? If we're being technical here, only bento bags and and frame wedges actually strap to the frame and they never hold much else than a spare tube and a small multi-tool (if that).
There's always the Jandd frame bag and the full-triangle deals like the one below that...