I had the answer to this one emailed to me yesterday. Download a copy of the GAR form, there are several websites with one (Gloucester Staverton?) onto your ipad. Get yourself an app to edit .pdf files, there is one for ipad. Edit the empty form with all of the stuff that relates to your aircraft and yourself so that when abroad your only need to enter the minimum info, time, date and port of entry ie the stuff that will always be the same.
Don't forget to look up all of the email addresses for the police, customs and excise etc. and save them on your pad.
I want to do the same but on a Winders netbook, thread on PPRuNe already asking about pdf editors for PC.