Can be run from the script menuextra if saved as an application,
or by a Folder Action via AppleScript or Automator (probably easiest).

THERE MAY BE ISSUES WITH REPLACING FILES. Script *should* die in that event (untested).
Trying to keep read_array() and write_array() as generic as possible for use else where. *hint-hint*
Doing a lot of re-reading of the plist array to be able to repeat functions after adding to or deleting from it
Property list array delimiter is "%%"

Structure
----------------
Start
Count items to import.
If nothing to count: Add folder
If > 0: ask to import, manage folders, or cancel.
Else: Manage folders.
If mange folders: Ask to add, or remove folders, prompt for another, Start.
If import: Ask to delete from device
If delete: Move items to temp dir, tell iPhoto to import temp dir
(iPhoto is slower than the script and does not return true or false on completion of import.
Make iPhoto work away from the folders so the script doesn't run ahead deleting items.
Unfortunately telling Finder to "move" a file from one disk to another leaves the original
so we are 'rm 'ing the files one by one as they are moved.
Also there are no auto increments in the case of multiple files with the same name.)
Else: Tell iPhoto to import folders.
If cancel:

*)

property the_dom : "iphoto.import.this"
property the_key : "folders"
start()

on start()
set import_folders to read_array(the_dom, the_key)
if import_folders is not false then
set image_count to count_folder(import_folders)
if image_count is greater than 0 then
set start_button to button returned of (display dialog (image_count as text) & " items in import folders." buttons {"Cancel", "Manage Folders...", "Import..."} default button 3)
if start_button is "Import..." then
import_files(import_folders)
else
manage_folders("You rang?")
end if
else
manage_folders("No items to import.")
end if
else
add_folder()
end if
end start

on import_files(import_folders)
set import_button to button returned of (display dialog "Delete imported items from device?" buttons {"Cancel", "Keep", "Delete"} default button 3)
if import_button is not false then
try
set the_date to (month of (current date) as string) & " " & day of (current date) & " " & year of (current date) & " " & hours of (current date) & "h" & minutes of (current date) & "m" & seconds of (current date) & "s"
tell application "Finder"
set temp_folder to (make new folder at (path to temporary items folder) with properties {name:the_date}) as alias
repeat with i in import_folders
set these_items to every item of folder (i as POSIX file)
repeat with ii in these_items
move ii to temp_folder
if import_button is "Delete" then
do shell script "rm " & quoted form of (POSIX path of (ii as alias))
end if
end repeat
end repeat
set import_folders to {POSIX path of temp_folder}
end tell
on error theMsg
display dialog theMsg
end try
tell application "iPhoto"
activate
try
repeat with i in import_folders
import from i
end repeat
end try
end tell
end if
end import_files

on manage_folders(the_dialog)
set import_folders to read_array(the_dom, the_key)
set manage_button to button returned of (display dialog the_dialog buttons {"Cancel", "Delete Folders...", "Add Folder..."} default button 1)
if manage_button is "Add Folder..." then
add_folder()
else
if manage_button is "Delete Folders..." then
delete_folders()
end if
end if
end manage_folders

on count_folder(import_folders)
set item_count to 0
repeat with i in import_folders
try
set item_count to item_count + (do shell script "ls '" & i & "' | wc -l")
on error errMsg
display dialog errMsg
end try
end repeat
return item_count
end count_folder

on add_folder()
set import_folders to read_array(the_dom, the_key)
try
set this_folder to POSIX path of (choose folder)
on error
start()
end try
if this_folder is not false then
-- write_array will return true on success or an error if a duplicate entry is found.
set is_written to write_array(the_dom, the_key, this_folder, import_folders)
if is_written is true then
set add_button to button returned of (display dialog ((this_folder) as text) & " added to import list." buttons {"Back", "Another"})
if add_button is "Back" then
start()
else
add_folder()
end if
else
display dialog "Oops!: " & is_written
manage_folders("You rang?")
end if
end if
start()
end add_folder

on delete_folders()
set import_folders to read_array(the_dom, the_key)
set new_folders to ""
set the_goner to choose from list import_folders with prompt "Choose folders to remove from the import list." OK button name "Delete" with multiple selections allowed
if the_goner is not false then
repeat with i in import_folders
if i is not in the_goner then
set new_folders to new_folders & "\"%%" & i & "%%\","
end if
end repeat
set new_folders to characters 1 through ((count of characters of new_folders) - 1) of new_folders as string
do shell script "defaults write " & the_dom & " '{ " & the_key & " = (" & new_folders & "); }'"
end if
start()
end delete_folders

on read_array(the_dom, the_key)
try
set {tid, text item delimiters} to {text item delimiters, "%%"}
set read_plist to text items of (do shell script "defaults read " & the_dom & " " & the_key)
set str2array to {}
repeat with i from 2 to (count read_plist) by 2
set this_item to item i of read_plist
set end of str2array to this_item
end repeat
set text item delimiters to tid
return str2array
on error
return false
end try
end read_array