redirect mobile devices

One tiny suggestion:

You can remove the / in the redirect between the hostname and [HTTP::uri]:

when HTTP_REQUEST {
    switch -glob [string tolower [HTTP::header User-Agent]] {
        "*blackberry*" -
        "*ipad*" {
           HTTP::redirect "http://m.mysite.com[HTTP::uri]"
        }
        default { log local0. "Device Access Attempt [HTTP::header User-Agent]" }
    }
}

Also, you don't need the return in the switch statement as only one switch case will ever get executed.

Aaron