[csuper]

Have you considered Evernote? You can input text or take photos. Then tag them all to keep it organized.

[Murkin]

I would prefer a more formal way to ensure order. For instance, dedicated field for name, phone, email.

And the ability to cross-reference this information with linkedin and other entries

(e.g. all contacts I have in law firm X)

[bhousel]

I second the Evernote suggestion..

Search in handwritten or scanned notes works surprisingly well, and tagging features make organization of business cards simple..