when i put 1 custom ringtone in my iphone a little pop up said, your almost at limit of memory would you like to diss miss, just wondering if any1 else has had this problem and if there is a way to upload more ringtones with out that pop up.....

i get that little pop up too, only since i downloaded a heap of crap with installer.
it asks you to delete photos or songs to free space even though i have 6GB free.
i have just been ignoring so far.

i'd been keen for more info

i believe its because the OS partition is separate, and that 6gb is the USER partition, you need to do some links in the terminal and such

I've had the warning several times, it's never actually completely filled up... so im just wondering if it auto-overflows into the user part when it caps out... seems that way

Yes that's correct, if you have a terminal app installed or you ssh into your iPhone and run "df -h" you'll see the partition map.

There's only 30MB (from memory) on the Applications partition.

There are ways around this, a lot of people simply create the Applications folder as a symbolic link to the other partition which then gives you full access to the 8GB (or 4GB)

There's a few steps involved but plenty of tutorials around if you google it. I've not done it so I can't tell you 100% if it works without problems.