Portable tools that can be used to defragment your hard disks
PageDefrag is a free portable defragmenter that allows you to defragment files that you might otherwise be unable to defragment with typical defragmenting tools. Files such as registry, paging, event log and hibernation files or those that are open for exclusive access are just a few examples of what this
UltimateDefrag (Freeware Edition) is a Free Portable Defragmenter that "allows you to optimize your hard drive any way you want". This free defrag tool enables a user to not only defrag files on a disk, but also put frequently accessed files in areas on your hard drive where they will achieve maximum performance.