A memory card is almost like a hard disk. The space on the memory card must be divided into clusters for further data storage. The smaller the cluster, the more efficient the storage process will be. The cluster size of a memory card formatted in the FAT system is bigger than that of a FAT32.
What is that related to me
Imagine each cluster as a brick (which has fixed storage capability of 20). In FAT system, that brick is divided into 4 parts and each part can store 5 totaling a sum of 20. In FAT32 system, each brick is divided in to 10 parts and each can store 2 totaling 20 as well. A piece of info needs to be stored in that brick. The size of that info is 6. In the FAT system, the sequence of filling goes like this: The 1st part is filled with 5 and the 2nd part will be filled with 1. When the next info needs to be stored, it will start filling in the 3rd part, because the 1st and 2nd parts are already allocated for info 6. What does that mean Part 2 has a remaining waste space of 4(unusable since it is allocated for info 6) and the remaining storage space of the brick is 10 only. Storing the same bit of info (size 6) in a FAT32 system yields in allocating 3 parts for that info and leaving the remaining 7 parts for further use. So the remaining storage space of the brick will be 14.
That is the meaning of efficient storage
In order to convert your memory card from FAT to FAT32, you must insure both the memory card and the device you intent to use in, support FAT32 system. Handheld devices like PPCs support FAT32, so its up to the memroy card. If you insert your memory card in a memory card reader that is connected to your desktop, from within the desktop environment right click the corresponding letter of your memory card and chose "Format...". If your memory card supports FAT32, then you can format it in a FAT32 system.
DISCLAIMER! FORMATTING YOUR MEMORY CARD WILL ERASE ALL DATA ON THE CARD! SO BE SURE TO EMPTY THE MEMORY CARD BEFORE CONVERTING IT FROM FAT TO FAT32. ANY LOST OF DATA,DAGAMGE TO THE MEMORY CARD OR PDA IS NOT THE RESPONSSIBLITY OF PPCD OR ANY ADMINSTRATION MEMBER!
You will really feel the effect if you have a lot of small size files (like agenda fusion icons); which leads us to another important issue...IS IT WISE TO STORE THOSE ICONS ON A MEMORY CARD? OR TRY TO INSTALL THEM IN THE ROM (WHERE THERE ARE NO CLUSTERS)? I tried it and you will be shocked
about the results 
