I can't sync photos from my iPhone 3gs to my mac
iCloud backup works if you have iOS6.  You must be connected to wifi and plugged into the charger for this to work. 
http://9to5mac.com/2013/09/17/getting-ready-for-ios-7-how-to-backup-your-device-setup-ios-7/

iOS 5 should be able to backup / sync via WiFi  Google "How to Set Up Wi-Fi Sync in iOS 5" 

If iCloud doesn't work for you... you should be able to save your photos using dropbox:  http://www.idownloadblog.com/2013/08/15/back-up-iphone-photos/