You can subscribe to SAP Notes to receive notifications when they are updated

See:
http://sapport.blogspot.be/2009/06/subscription-to-updates-of-sap-notes.html

http://sapport.blogspot.be/2011/02/receiving-sap-notes-updates.html

Where can I maintain those note subscriptions?
If you are regular customer (with valid license of SAP products) you can request the list of notes you subscribed via customer message under the user component xx-ser-sapsmp-usr.

In case your OSS ID is same as mine (certified consultant w/o license to SAP software, you can request SAP directly to open the customer message on behalf of you.