They are a reasonable approach. Cisco and Cabletron both have solutions available in their access points. However, for a truly secure wireless LAN, you should use a VPN, instead of just using these WEP bandages.
For more information on this topic, visit these other SearchSecurity.com resources:
News & Analysis: Thinking about wireless security
Scheier's Security Product Roundup: Flawed wireless LANs inch their way to acceptance
Ask the Expert: How to secure a wireless LAN