Credit-card holders post a specific hashtag on Twitter to trigger payments from their accounts.

BBC: American Express launches purchase-via-Twitter service

SmugMug account holders also can opt to post photos to several sharing sites at the same time with one click.

WSJ: The Digital Solution: A Photo App That Makes 'Awesome' a Verb

Some current holders may want to sell before the 180-day post-IPO "lockup" period, during which insiders and investors generally aren't permitted to sell their stock.

WSJ: Hot Item: Pre-IPO Facebook Shares

Post-transaction, SoftBank will own approximately 70% and Sprint equity holders will own approximately 30% of New Sprint shares on a fully-diluted basis.

ENGADGET: Softbank confirms 70 percent Sprint acquisition for $20.1 billion