mobileFix for Google Apps "Unknown error" on webOS
So it turns out the problems I was having with my Google Apps account under webOS were caused by Google setting all sync operations to use HTTPS rather than HTTP (which makes sense - I didn't actually realise all my data was being sent unencrypted between me and Google previously!). They must have rolled it out to the Apps users first as it has been broken for a while, but starting on April 1st everyone using Google has been affected.
This is actually good news for me - before there were only a few of us using Google Apps on webOS, and we were struggling to get it working (I had actually gone back to my Android mobile as without Google integration I can't use my phone (no contacts, calendar, Google chat etc)), but suddenly everyone using a Gmail account couldn't sync and so the webOS user base sprung into action and thanks to the efforts of two forum members over at webOS Nation we now have a patch to get it all working again. Grab it here.