diff --git a/src/main.cr b/src/main.cr
index 801443f..72522ab 100644
--- a/src/main.cr
+++ b/src/main.cr
@@ -1,34 +1,6 @@
 require "tap"
 require "option_parser"
 
-args = Array(String).new
-
-OptionParser.parse! do |parser|
-	parser.banner = "usage: tap-aggregator <command> [options]"
-	
-	parser.on("-h", "--help", "Show this help") do
-		puts parser
-		exit 0
-	end
-	
-	parser.invalid_option do |flag|
-		STDERR.puts "ERROR: #{flag} is not a valid option."
-		STDERR.puts parser
-		exit 1
-	end
-
-	parser.unknown_args do |x|
-		args = x
-
-		if args.size < 1
-			puts parser
-			exit 1
-		end
-	end
-end
-
-command = args[0]
-
 class Storage
 	def initialize(@root : String = "storage")
 	end
@@ -71,6 +43,49 @@ class Storage
 	end
 end
 
+args = Array(String).new
+show_projects =     [] of String
+show_environments = [] of String
+show_revisions =    [] of String
+
+OptionParser.parse! do |parser|
+	parser.banner = "usage: tap-aggregator <command> [options]"
+	
+	parser.on("-h", "--help", "Show this help") do
+		puts parser
+		exit 0
+	end
+
+	parser.on("-p id", "--project id", "Filter results that do not match this project.") do |id|
+		show_projects << id
+	end
+
+	parser.on("-e id", "--environment id", "Filter results that do not match this environment.") do |id|
+		show_environments << id
+	end
+
+	parser.on("-r id", "--revision id", "Filter results that do not match this revision id.") do |id|
+		show_revisions << id
+	end
+	
+	parser.invalid_option do |flag|
+		STDERR.puts "ERROR: #{flag} is not a valid option."
+		STDERR.puts parser
+		exit 1
+	end
+
+	parser.unknown_args do |x|
+		args = x
+
+		if args.size < 1
+			puts parser
+			exit 1
+		end
+	end
+end
+
+command = args[0]
+
 storage = Storage.new
 
 enum Tap::Entry::Status
@@ -96,9 +111,23 @@ when "add"
 
 	storage.store project, environment, revision, STDIN.gets_to_end
 when "show"
-	storage.projects.each do |project|
-		storage.environments(project).each do |environment|
-			storage.results(project, environment).each do |revision, timestamp, suite|
+	projects = storage.projects.select do |project|
+		show_projects.size == 0 || show_projects.any? &.==(project)
+	end
+
+	projects.each do |project|
+		environments = storage.environments(project).select do |environment|
+			show_environments.size == 0 || show_environments.any? &.==(environment)
+		end
+
+		environments.each do |environment|
+			# FIXME: This currently parses everything, including entries
+			#        that are not going to be displayed.
+			results = storage.results(project, environment).select do |revision, timestamp, suite|
+				show_revisions.size == 0 || show_revisions.any? &.==(revision)
+			end
+
+			results.each do |revision, timestamp, suite|
 				puts "#{project}, #{environment}, #{revision} (#{timestamp}) [ #{suite.size} tests ]"
 				suite.each do |test|
 					puts "  -> #{test.id} #{test.status} #{test.title}"