After the OS update, my wireless speeds have dropped to a crawl. around 350 to 500 kps on my home wlan. Every other device on my wlan runs between 6 and 10 mbs. I've only found posts about deleting the wireless network, recycling the router and then creating a new connection. Obviously I don't have access to every wireless router I connect to in able to do this and the connection is consistently slow no matter what network. Any suggestions on how to fix this?
I would first try resetting your PRAM, then create a new network location.
Once you've done so, delete your network locations in System Preferences and create a new, fresh location.