Most handy for fixing those pesky exhaust gaskets and collets. A tiny, and I mean tiny blob of Blu Tac on the exhaust gasket, on opposite sides of the circle (180 degrees apart) will hold the little demons in place while you fit the system, its a good idea to give the port a wipe with a rag first to remove any loose flaky crud. Laggy bands (elastic bands to posh people) will hold the collets in place on the headers until the clamps go on and are partly tightened. Snip the laggy band with a scalpel or a pair of scissors, then pull the remains out. Start the bike, the Blu Tac will smell for about ten seconds once it gets hot but that's all, no more smell after initial start up. A blob of Blu Tac is also great for blocking up holes or whatever, wherever you don't want something else to get into, as in a temporary masking for odd or otherwise difficult shapes to mask.