Spaces is nice, but there doesn't seem to be any easy way to quickly assign a particular application to one (or all) spaces.  You have to go to the preferences and even then you don't get a list of running apps, you have to go find the application in question.

I made an attempt to fix this, but I ran into a scripting issue, namely, how do I set a value in the "application bindings" record.  The keys are bundle names of the form |com.cocoatech.pathfinder| and I had enough trouble getting the list, let alone setting them.  Here's what I have so far, any thoughts?

Applescript:

tell application "System Events"
   set all_spaces to "65544" -- application is in all spaces
   set choose_file to "Choose a file…"
   set num_spaces to 0
   set app_layout to {}
   tell spaces preferences of expose preferences
       set num_spaces to spaces rows * spaces columns
       set app_layout to application bindings
   end tell
   
   -- Okay, please tell me there's a better way to get the names from a record!
   try
       get properties of app_layout
       display dialog "Whoops, we expected this to fail. Let the poor programmer know."
       return false
   on error errstr
       set app_locations to {}
       set state to "NEEDID"
       set curid to ""
       repeat with w in words of errstr
           set w to w as string
           if state = "NEEDLOC" then
               set app_locations to app_locations & {curid, w}
               set curid to ""
               set state to "NEEDID"
           else if state = "NEEDID" then
               if w = "|" then set state to "INID"
           else if state = "INID" then
               if w = "|" then
                   set state to "NEEDLOC"
               else if curid = "" then
                   set curid to w
               else
                   set curid to curid & "." & w
               end if
           end if
       end repeat
   end try
   
   set app_info to {name, bundle identifier} of (application processes whose background only is false)
   set app_list to {}
   repeat with i from 1 to length of (item 1 of app_info)
       set app_name to (item i of (item 1 of app_info))
       set app_bundle to (item i of (item 2 of app_info))
       set app_location to ""
       if app_locations contains app_bundle then
           repeat with i from 1 to count app_locations by 2
               if app_bundle = item i of app_locations then
                   set app_location to item (i + 1) of app_locations
                   exit repeat
               end if
           end repeat
       end if
       if app_location = all_spaces then
           set app_list to app_list & {"All" & tab & app_name}
       else if app_location ≠ "" then
           set app_list to app_list & {app_location & tab & app_name}
       else
           set app_list to app_list & {tab & app_name}
       end if
   end repeat
   
   set app_name to (choose from list ({choose_file} & app_list) with prompt "Pick an application to assign.")
   if app_name is false then return false
   set app_name to item 1 of app_name
   if app_name is choose_file then return true -- for now
   
   set app_index to -1
   repeat with i from 1 to length of app_list
       if app_name = item i of app_list then
           set app_index to i
           exit repeat
       end if
   end repeat
   if app_index = -1 then
       display dialog "Couldn't find application name in list! Internal error."
       return false
   end if
   set bundle_name to item app_index of (item 2 of app_info)
   set app_name to item app_index of (item 1 of app_info) -- name without the tab stuff
   --return {app_name, bundle_name}
   
   set space_choice to {"None", "All"}
   repeat with i from 1 to num_spaces
       set space_choice to space_choice & i
   end repeat
   set new_space to (choose from list space_choice with prompt "Assign a space to " & app_name)
   if new_space is false then return false
   set new_space to item 1 of new_space
   if new_space = "All" then set new_space to all_spaces
   if new_space = "None" then return false -- for now
   
   -- now the critical test, can we do this?
   tell spaces preferences of expose preferences
       set bundle_name of application bindings to new_space
   end tell
   -- nope. What's the magic to change this record?
   (*
       {|org.tynsoe.buddypop|:65544, |com.adiumx.adiumx|:65544, |at.obdev.launchbar4|:65544, |com.cocoatech.pathfinder|:65544, |org.orange-carb.slimbatterymonitor|:65544, |com.wbc.omnigrowl|:65544, |com.growl.growlhelperapp|:65544, |com.apple.ichat|:65544, |com.apple.mail|:3, |com.gorter.antirsi|:65544, |com.yousoftware.youcontrol|:65544, |com.growl.menuextra|:65544}
   *)
end tell