serving autogenerated files to users

hi everybody,

my rails app generates a pdf specially made for a user after they
finish filling out a set of online forms. i used pdf-writer to generate
the pdf on the fly which works quite nicely.

my question:
where should i generate the files to if i want the user to be able to
download them after they generate? anywhere in the public folder? also,
what is the 'default' path? public? so if make a hyperlink that has
href="/pdfs/cust1.pdf" would that point to RAILS_ROOT +
'/public/pdfs/cust1.pdf' ???

anything else i need to look out for? also, i don't plan on keeping
these pdfs on the server forever.. whats a good way to check if they're
stale and delete them if necessary? i think we are hosting this
ourselves so it could be a crontab.

thanks in advance,

Stuart (the other stuart)