Currently, if you want to transfer land between friends for "free", the only way to do so is through the land sales interface.
This has serious issues when trying to move land from owned by yourself to owned by a group of yours. If your tier is maxxed out, the only way to do so is sell to a trusted 3rd party, deed your tier to group, then hope he is trustworthy enough to sell back to you.
For land barons, used to the land sales interface, checking that box to sell to a specific person is a routine event. Most people aren't so used to selling land, and that interface is intimidating. If you aren't familiar with it from repeated use, it is extremely easy to sell teh land publicly for a single linden by accident while trying to effect a transfer for the purpose of grouping your land.
I know you could add any number of warnings to the land sales interface, but that won't really protect those unfamiliar with the sales interface, because the entire interface is unfamiliar to them.
So, with that in mind, a few suggestions....
1) Any time any kind of land transfer is made, for any reason, the seller has a 5 minute cooloff period in which they can unilaterally revert the sale (reverts both land sale and any money that changed hands). During this period, the buyer cannot resell the land, but is not otherwise affected.
2) A completely separate interface for gifting land. The fact that land sales and land gifts are made through the same interface, and the mistakes that those unfamiliar with this interface make, is what enables land vultures to work. This does of course mean yet another window interface, but at least if that one is opened by a "give land" command instead of a "sell land" command, it makes it simpler to understand from a natural language perspective.
3) A method to transfer land and its associated tier simultaneously and directly from your personal ownership to the ownership of any land group that you are a member of. This would completely circumvent the need to involve a 3rd party in grouping up the land.
Comments?