"Compared to other "password keeper" programs, CryptoTE does not force any structure upon your data: it works with plain ASCII text and does not require you to fill in grids, key-value attributes, descriptions etc. Encryption is transparently performed..."

This is the reason I wrote Encrypted (https://github.com/srpeck/encrypted) - a single 21KB HTML file plaintext editor that uses SJCL to encrypt all data persisted to localStorage or disk. As a consultant I am often provided a work machine that I cannot install anything on - but there is guaranteed to be a browser.