64-bit Cisco VPN client (IPsec)?
Solution 1:
Hmm, nobody mentioned Shrew Soft VPN Client yet ? It's a free (as in beer) and cross platform VPN client that compatible with Windows 64 bit. Although free, but support from the author has been great. Currently it doesn't support hybrid xauth+certificate mode but the feature will come soon.
Lancom also provides a 64 bit VPN Client for Windows, but IMO they just resell/rebrand NCP's Client.
You can also try TheGreenBow VPN Client, which is a bit cheaper (56 EUR) than NCP/Lancom's client.
Solution 2:
I just tried this free IPsec VPN client, it works well in vista x64 and win 7 RC x64. I was also able to import a cisco .pcf directly into shrew. Just select the pcf file and import.
www.shrew.net/software
Shrew has supports for windows, linux and BSD
There is no need to buy NCP
Solution 3:
Cisco now supports the 64-bit OS with an IPsec VPN client, see Release Notes for Cisco VPN Client, Release 5.0.07.