Allow people to find one-off or longer term ways to volunteer their skills with start-ups.
The concept of volunteering is familiar to all of us. What if we apply that to start-ups, and had a dedicated site where start-ups could post needs and people could volunteer to share time and skills?
The site could be simple: one page on which start-ups list needs and any location restrictions, another on which people list skills they're willing to share. Each would be searchable. A further step could be to automate matching possibilities.