There is a shareware utility available to read and send messages on any gsm phone with built in infrared, serial, or bluetooth, not just nokias.
This software can be downloaded from www.strongcube.com. All you need to do is make sure your handset is registered as a modem device on your PC, and therefore is allocated a COM port.
This program however, can only be used to send sms and manage existing messages on your phone, but does not automatically notify you upon incoming messages. So this is more like a utility for managing messages on your phone, where you may find it handy to copy and paste messages, sender phone numbers, etc.
More or less like what the nokia PC suite does. The difference is I think If i'm not mistaken, nokia PC suite does backup of your messages on your PC as well. This one however, sadly doesn't, but good enough for non nokia users!