Some questions could be asked on multiple SE sites, for example this gamedev question is likely to interest some users of math.SE. Since cross-posting is rather discouraged (for a good reason) it might be a nice feature to let some users1 give these questions a "would also be nice on [other SE site]"-vote2. Then the 10 most recent questions with, say, five such votes3 are displayed on that other SE site's question list - in a separate section or mixed with other questions plus the site logo, I don't know which would be better.
1) say, with 500 rep on both sites
2) that might also include suggesting target site tags
3) from those sites that have valid migration path connections unless a mod is involved