Can I forward/reply calls/sms to PC?
Edit 2014/06: I've moved on and developed MAXS. See my answer here.

Original Answer:

GTalkSMS (Google Code Project Page) is a alternative for android-notifier which works over XMPP (GTalk, Jabber). It allows you to control various aspects of Android, includes a SMS/Call/Battery notification and reply system. Additionaly it is able to send and receive files to and from your Android device. There are many other features too.

Using XMPP as transport, the "desktop app" can be every XMPP Client. Which is one of GTalkSMS big advantages, as it does not need a dedicated desktop app.

Note: According to the FAQ I have to disclose that I am involved in GTalkSMS. GTalkSMS is an open source GPL licensed Android app. Everyone can contribute.