Quick and dirty but it will do

lib/pingdom/client.rb

@@ -40,6 +40,11 @@ def get(uri, params = {}, &block)
       update_limits!(response.headers['req-limit-short'], response.headers['req-limit-long'])
       response
     end
+
+    def post(uri, params)
+      response = @connection.post(@connection.build_url(uri, prepare_params(params)), nil, "App-Key" => @options[:key])
+      response
+    end
 
     def update_limits!(short, long)
       @limit ||= {}
@@ -63,6 +68,15 @@ def test!(options = {})
     def checks(options = {})
       Check.parse(self, get("checks", options))
     end
+
+    REQUIRED_FOR_CREATE = [:name, :host, :type]
+    def create_check(options = {})
+      missing_keys =  REQUIRED_FOR_CREATE - options.keys
+      raise ArgumentError, "#{missing_keys} required" if missing_keys.any?
+
+      Check.parse(self, post("checks", options))
+    end
+
     def check(id)
       Check.parse(self, get("checks/#{id}")).first
     end

pingdom-client.gemspec

@@ -1,6 +1,6 @@
 Gem::Specification.new do |s|
   s.name = %q{pingdom-client}
-  s.version = "0.0.6.alpha.af2"
+  s.version = "0.0.6.oib"
 
   s.required_rubygems_version = Gem::Requirement.new(">= 0") if s.respond_to? :required_rubygems_version=
   s.authors = ["Matt Todd"]
@@ -25,7 +25,7 @@ Gem::Specification.new do |s|
     "lib/pingdom.rb",
     "lib/tinder/faraday_response.rb",
     "Rakefile",
-    "Readme.md",
+    "README.md",
     "spec/pingdom-client_spec.rb",
     "spec/spec_helper.rb"
   ]