Gmail Chat has finally added the ability to mask your presence - the one feature which to my IM-phobic mind makes instant messaging bearable. The Google Operating System has written up the new feature, which allows you to set your status to "Invisible". This has obvious productivity benefits - you can check and see if your contacts are online, but won't be bothered by anyone trying to contact you.
Note, however, that if you use other flavours of Google Talk (ie the gadget or desktop app) you won't be able to change your status to invisible because they don't support the new feature yet - it's been applied to Gmail Chat first. It's also only available for the new version of GMail (supported in IE7 and Firefox 2).
Earlier today we showed you how to set your Google Talk status to "idle", but if you don't to be pinged with "Are you there?" enquiries, the "Invisible" setting may be the way to go.
Invisible Mode in Gmail Chat [Google Operating System]