Copy Photos (& Videos) Between iOS Devices
Or you can use Dropbox.
How to Setup Dropbox on the iPad
If you are with your client, I recomment using AirDrop to transfer photos from your iPad to his/her iPad. Here's a KB article on how you can accomplish this: http://support.apple.com/kb/PH3147?viewlocale=en_US
If you are not near your client, I would use Dropbox. Set up a shared Dropbox folder and copy photos to that folder. Share the folder with your client.
Hope this answers your question!