Co-founder of Bike Hacks, and now mainly just reader for the most part, Brendon sent along the following hack for on-the-road spoke repair. In some cases it might be necessary to remove your cassettee and this tool will help you do it - while not bogging you down. All text and photo credit below goes to http://www.m-gineering.nl/nbtg.htm:
On-the-road spoke replacement tool -Next Best Thing 2 Cassette Tool
If you're on a long distance cycling trip and you break a spoke (a common occurrence) on the right hand side of your rear wheel then you're in trouble.
To replace these spokes you need to remove the cassette to get access to the hub. Normally this requires a specialized tool, a very large spanner (about 12") and a large chain whip - all of which are heavy and unwieldy to carry. However, the Next Best Thing 2 is a small and light tool that enables you to remove the cassette using just the leverage of the bike's chain.
Assuming you have the correct spokes with you (as any serious long distance cyclist would) then you should be good to go again without having to limp in to the next town/bike shop - something I've had to do several times over the years.
This is probably in the category of "tool you very rarely use but are extremely grateful when you do."
[Note: Instructions on how to use the tool can be found here. --OH]
NBT2 Next Best Thing 2 Cassette Lockring Remover