The virtual world experience sometimes can be impeded when one has has an out-of-control inventory containing hundreds, if not thousands, of items that need to be waded through before find the item one was looking for. It only takes a little bit of time, some energy, and maybe a scripted organizer or two to sort through the various folders of inventory and determine what needs to be kept and what needs to be sent to the trash. It very well may need to be spread over several sessions.
First, it is important to determine what types of items will be processed during each session. Perhaps during one session only freebies found during the many in-world hunts will be sorted, another session might be set aside for sorting textures, a third session could be sorting anything named “Object”, and so on. Breaking the process into small pieces process one-at-a-time can make it seem more manageable and worth the effort.
Unless you are a very sentimental person the task of dividing items into only a few piles (one reserved for everything going into the trash to be purge later). The likely piles will consist of those items expected to be used on a regular basis, items that need to be kept but kept in storage (i.e. moved into the contents tab of a rezzed box object and then taking that box object into inventory), or perhaps a third pile for no-copy transferable items to be given away or sold to others in a virtual yard sale.
While not required, some find it useful to utilize an organizational tool such as a scripted texture sorting tool or a pose stand where animations and gestures can be moved into it and then the tool itself is only rezzed on an as-needed basis. Once everything is organized into a system unique to the user (after all, they are they only one that is going to access their own inventory window within the virtual world viewer) time will be saved and the performance of their system should improve everything.