You really like the update functionality in the joomla 2.5 installer? We do too, but we got kinda bored. Each time we wanted to check if there are any new extensions updates we had to login into our website, go to the extension manager -> click update -> click find updates -> wait 5sec -> if there is nothing - well done dear, but you'll have to come again tomorrow...
O. Schwab got really bored by this routine and spoke with me about that 3 days ago. Then we thought - wouldn't it be great if there was a joomla plugin that could check for updates for us and send us a mail if there are! Well, there is one now!