Guess my Number - Code Golf
Ruby: 63 58 52 49 characters

puts"=-+"[r=$_.to_i&lt;=&gt;n||=1+rand(100)];r==0&amp;&amp;exit


Sample run:

bash-4.2$ ruby -ne 'puts"=-+"[r=$_.to_i&lt;=&gt;n||=1+rand(100)];r==0&amp;&amp;exit'
50
-
25
+
37
+
43
-
40
+
42
=