  We prove an endpoint version of the uniform Sobolev inequalities in
Kenig-Ruiz-Sogge [8]. It was known that strong type inequalities no longer hold
at the endpoints; however, we show that restricted weak type inequalities hold
there, which imply the earlier classical result by real interpolation. The key
ingredient in our proof is a type of interpolation first introduced by Bourgain
[2]. We also prove restricted weak type Stein-Tomas restriction inequalities on
some parts of the boundary of a pentagon, which completely characterizes the
range of exponents for which the inequalities hold.
