Ex-Googlers that worked on Wave are bolting a feed-based UI on top of Gmail at Fluent. They’re also promising “instant search” style features and looking at time-based search. GigaOM Pro analyst Stowe Boyd calls it a spin on his “liquid email” concept, and wonders if it will support an open follower model. PC World mentions that email plug-ins that import social network contact info are readily available, but Fluent’s approach isn’t aimed at being social that way. Rather, it’s all about the user interface. And about letting a user whiz through multiple email accounts.