Being from the Philippines, the SMS capital of the world, we are fond of connecting our mobile phones to computers to manage it, e.g., send/read/download/backup SMS, change ringtones, upload themes and wallpapers, etc. The most popular linux application is Gnokiii, at least to me.
I just found out that there are other open source applications out there. Unfortunately, I no longer connect my mobile phone to my computer since it, in itself, is a miniature computer. :)