How to politley tell ppl we don't really want commerative stuff for a baptism?

This might sound awful but is there a polite way to include on the invite that we don't really want any commerative stuff, like cups and engraved spoons and bracelets, for a baptism? Money is a bit tight and we would really prefer things like books, clothes and toddler toys, rather than dust collectors.
Can anyone think of a polite way to say it? Are there any poems, like those 'we have the sheets and the kitchen bin, since we've already lived in sin' ones they use for wedding invites?

Could you do a baby registry and include it with the invites maybe?

My suggestion would be the same as Kel's - set up a gift registry somewhere and include with the invite. No matter what you request, there will always be some that will still get you something commemorative though.

Thanks ladies. Duh, why didn't I think of that? Sleep deprivation kicking in again....