AttachmentSaver is a new application that adds an extension which allows you to save your email attachments on your iPhone. This feature should be available by default but for some obscure reasons, Apple hasn’t deemed it necessary…
AttachmentSaver gives you the ability to download attachments of all types, whether supported by the Mail.app or not, and save them into a folder on your iPhone disk.
Files are downloaded to ~/Library/Downloads (/private/var/mobile/Library/Attachments) and it’s recommended to install iFile to access the attachments you download.
This app is available from the Cydia Store for $1.99.