Krypt is a KDE GUI for managing volumes encrypted with LUKS.
Krypt is a simple application that sits in the tray, and provides easy acces to the list of volumes encrypted with LUKS, that are present in the system. It is possible to quickly decrypt, encrypt back, mount and umount such devices. It also monitors HAL activity, and responds by showing a pop-up with password prompt. When the password is provided KDE's media manager kicks in and does all the job. If it doesn't, which can happen if the device was previously used and then removed (in that case KDE still thinks it is there and doesn't respond with the popup) it is possible to mount it using Krypt's menu entry.
Krypt will mount the volume in exactly the same place where KDE's media manager would do that. Krypt also has a list of ignored devices, where user can place all the volumes that he doesn't want Krypt to handle (for example any permanently decrypted and mounted partitions, like encrypted /home). Another useful option makes Krypt automatically encrypt all volumes that are umounted (for example by using KDE media manager's 'Safely remove' option).
Krypt is based on Kryptomedia tool, created for OpenSuse as a patch for original KDE. The drawback of that solution (at least in other than OpenSuse distributions) was that whenever KDE was updated some of its files had to be modified to get kryptomedia working. This program doesn't need any patches to KDE.
Krypt needs HAL and DBus daemons running, so before complaining that it doesn't work, make sure that both these services are working. It is possible, that when you plug in encrypted device, Krypt's password prompt shows up, but even after entering correct password it doesn't disappear, and following attempts to enter it give only an error message, that this device is already mapped. This is not Krypt's fault. It is because HAL can't handle cryptosetup (which is a program used for managing LUKS volumes) properly. To solve this problem you need a version of HAL patched with this: cryptsetup_temp.patch.