Why is my activity not tweeted or posted to Facebook wall once I upload it to Garmin Connect?
Garmin Connect checks for new activities on Garmin Connect every 5 minutes. So there may be a small gap between uploading to Garmin Connect and publishing to Twitter and Facebook.
How do I change the format of my tweets?
Simply visit the Garmin Social site and specify your Garmin Connect username, define the template and submit it. If you're updating a template and are signed-in on Twitter you won't need to reauthorize since you already did that earlier when you specified the previous template.
What if my tweet gets to long?
If after replacing the activity details the tweet is longer than 140 characters, Garmin Social will first trim the <title> activity element and if that's not enough, it will simply cut it off at 140 characters. You can already see this as you type your template for the tweets.
How do I discontinue using Garmin Social?
Go to your Twitter application settings on the Twitter site and revoke access for Garmin Social.
Can I include hashtags (e.g. #running) in my tweets?
Yes, that's possible.
Google+?
Google has not yet made an API available that enables other applications to post to someone's Google+ page. Once this API is available, support for Google+ will be added.

Due to unfortunate actions the Garmin Social service started to enthusiastically follow and invite uses. This was in violation with the Twitter rules and therefore Twitter suspended the @garminsocial account and is not willing to reactivate it. To get the service working again we had to open a new Twitter account @garmintweeter and have to ask users to setup there redo the setup of Garmin Social (the steps 1, 2, 3 on the Garmin Social homepage).

As a consequence of this issue, activities between February 17th and 21th may have been tweeted with a delay.