Well, for the sake of discussion, it might be worth identifying a few such tools. In certain cases it might be worthwhile to have a tool without a blade and a pair of folding scissors for those times you might be under too close of scrutiny for even a tiny knife blade.
About the best you will do is something like these:
http://www.keychain-tools.com/sebertech.aspThe Sebertech M2 and M3 come without knife blades and are a little over 3" when unfolded
For your purposes I'm sure you could find a cheap clone of this kind of tool in the $3-4 range.
Also for the sake of discussion, in cases like that a card-based tool such as a Tool Logic or a SwissCard could be carried with the blade component removed.
http://www.keychain-tools.com/tl_tld.aspAlthough depending on the circumstances this could also be confiscated for having too many suspicious ends being used for screwdrivers.
There was a Coleman tool that had removable components also a while back, the tools were sold in "cartridges" that fit in the knife. This tool's now out of production I'm pretty sure and it seems unlikely you'd be able to find enough parts for it to assemble a "complete" and bladeless tool.
Of course for the DIY types there's always the solution for a removable blade on a quality multi-tool posted on this very site:
http://www.equipped.org/alterpst.htmThanks as always to noted survival authority Douglas S. Ritter <img src="/images/graemlins/wink.gif" alt="" />
I still doubt you can get on a plane or a cruise ship though, even with a de-bladed leatherman. Anyone willing to try it?