Just started processing Shetland shape file. There are 549 polygons. There are 201,158 co-ordinates. Updated process:

1. Prepare a Word text file called Shetland.js which contains only var shetland = [ ];
2. In a copy of the file containing the data for Shetland, replace all ] ], [ [ with two <new line> in Word. Save.
3. In the same file, replace all ], [ with <new line> in Word. Save.
4. Get rid of dross at beginning and end of file. Save. You now have just co-ordinates, with a double <new line> between the set for each island.
5. Find first double <new line>.
6. Cut all co-ordinates preceding this. Save – you don’t want to risk doing this set twice.
7. Paste the clipboard into the online batch converter, then convert.
8. Copy the converted data into TextMate. Save.
9. Do the first RegEx to get rid of the dross from the conversion step. Save.
10. Do the second RegEx to replace all <new line>s with ], [, then save.
11. Add , [ [ to the beginning of the Textmate file, and ] ] at the end. Save.
12. Copy the whole of the TextMate file and paste it into shetland.js just before ]; (For the first set, you don’t need the initial comma.) Save.
13. Refresh the map webpage – another island will have been highlighted.