Agreed - Dropbox helps big time. I have the 5 free gigs of iCloud, but drop box will give you more flex. I have the 4 as well and it def comes in handy.
You can use iTunes on your desktop to manage memory on your device. For example, only sync select music and video content on your device instead of all of it, etc... You could also use more cloud storage for offloading text, data and images instead of leaving all of it on your device. Give free app Dropbox a try, for example.
I just got this phone recently &completely disregarded the gigabytes aspect of it. Are there any memory cards that I can use for my phone to create more space?