I wish to create a credit card applicatoin that must store xml and digital files. Are you aware any service on the web that enables me to keep files(digital most significant) and retrieve the files in the service after i need them? I am searching for something similar to flickr however with a choice of adjusting files trough webservices.

You can maybe use Amazon . com S3: http://aws.amazon . com.com/s3/

You should use their API to control your files from different conditions: