I'd love the opportunity to invest pro rata with angel groups, TechStars, Y Combinator, and many VCs. The "gimmick" factor would depend largely on the structure and presentation of the opportunity.

As it stands, it's exceptionally hard to buy the startup market. The closest thing we have to an Index fund is Ron Conway, and he's not selling shares of himself. This is a huge missed opportunity.

HNWIs and institutions have varied and limited access to deals, and are constrained in the number of investments they can make. This exacerbates the problem that early-stage angel investing has sickening variance unless you're able to build a sizable portfolio.

The general public can't get in on these deals at all.

Because of this, I'd love to see top investors accept, as a limited partner, a crowd-sourced, retail-accessible "Fund of Funds" that operated on something akin to the Vanguard business model, charging a fairly minimal fee to buy the startup market. If that existed, I'd joyfully invest in it.

edit: this would also provide an interesting benefit the startups, particularly if they're consumer-facing, as it would dramatically increase the number of people who have a reason to care about them, their product and their continued success.