How useful is a Thrush in Clojure ? (here, via @debasishg) - Thrush is a combinator that reverses the order of evaluation: Txy=yx. This article explores its potentials uses in Cojure, where it is less needed than in other languages like in Ruby. In Clojure, the Thrush combinator is the macro '->>'.
The introductory materials for #clojure 101 are online at RubyLearning, please read through them before the actual course starts! :-) (here, via @citizen428)
Clojure Protocols Part 3 (here, via @jneira) -- This article is the 3rd of a series explaining the use of 'protocols', a new feature in Clojure 1.2. In this article it addresses some changes of late in 1.2 that affects the syntax of protocols in subtle ways (that could break your code).
Converting a Custom Collection to a Sequence (here, via @AgileCarnival) -- Sometimes legacy code has custom collections that do not implement the Iterable interface and therefore you cannot use 'seq' to convert them to Clojure sequences automatically. This article provides some code to convert any collection that is accessed by an index getter (i.e. get(i)) into a sequence. Best of all is @stuarthalloway's comment about similar functionality being part of 1.2