Otherwise you could solder something to some unused pins (especially the whole row of non-GPIO pins at the opposite end of the board to USB). For example a ring crimp connector: http://uk.rs-online.com/web/p/crimp-ring-terminals/6881439/
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
I often use a cable tie if that helps.
Otherwise you could solder something to some unused pins (especially the whole row of non-GPIO pins at the opposite end of the board to USB). For example a ring crimp connector: http://uk.rs-online.com/web/p/crimp-ring-terminals/6881439/