If you can stand to have a separate tool, there are some oddball bicycling tools. The Topeak "Toolbar" is teeny, but takes regular size bits.

http://www.topeak.com/products/Tools/ToolBar

Or Countycomm has the "Versadriver":

http://www.countycomm.com/versadriver.htm

Or, you might find something like this small, offset ratchet.

http://shop4.frys.com/product/5311328?site=sr:SEARCH:MAIN_RSLT_PG
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John Beadles, N5OOM
Richardson, TX