rhino, nice idea, very difficult for us to impliment!! hacking the forum code to add such a facility is not a 5 min task, though i agree it would be useful.
Personally I use the resources of gmail and i use the forum "thread tools" menu to 1 subscribe to the thread so that i catch any new posts and 2 email the thread to one of my gmail accounts. Gmail then indexes the thread for me so that searching for the information at a later date is much easier ( i make extensive use of the subject line to put a concise description of the thread content into the mail sent to the gmail account.
It works for me and with Gmail giving 2Mb of storage per account i think i have plenty of room.
Try the advanced search facility, it works well.
PM me if you need an invite for a GMail account, i have plenty of invites spare
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