I wrote quite a lot about virtual disk support in Windows 7. I even gave some C# code on how to use it. Single thing that I haven't done is to actually make complete program with it. That is changed now.
Idea for this program is quite similar to VhdMount. Difference here is that this program uses native virtual disk support brought to you with Windows 7.
Since I hated necessity of going through Disk Management each time I want to perform attach (a.k.a. mount), there is also right-click support for .vhd files and for already mounted drives. Just select detach on any virtual drive's context menu and program will find itself which file that is.