If you have an older HTC device and would like to install Windows Mobile 6 you should hurry up. HTC announced that on the 31st October the download link for WM6 is going to be removed from their website.

Here is the original announcement:

16/10/08 – Windows Mobile® 6 Upgrade Deadline

October 31st is the last day to take advantage of the free upgrade to Windows Mobile® 6. The upgrade link will be removed from HTC’s website at 12:00 pm (noon) GMT on October 31st.

Removal of this free upgrade may affect users of the following devices: HTC S621, HTC S620, HTC P4350, HTC P3300, HTC Advantage.

If you haven’t upgraded yet and your device has a Windows Mobile® version lower than 6, please take advantage of this offer before it expires. To check the version on your device go to Start > Settings > System tab > About.