diff --git a/app/logical/post_sets/post.rb b/app/logical/post_sets/post.rb
index 6e8b3c21a..40fe31750 100644
--- a/app/logical/post_sets/post.rb
+++ b/app/logical/post_sets/post.rb
@@ -43,6 +43,10 @@ module PostSets
       tag_array.size == 1
     end
     
+    def is_empty_tag?
+      tag_array.size == 0
+    end
+    
     def current_page
       [page.to_i, 1].max
     end
diff --git a/app/logical/related_tag_calculator.rb b/app/logical/related_tag_calculator.rb
index 695cb712a..4e1543b94 100644
--- a/app/logical/related_tag_calculator.rb
+++ b/app/logical/related_tag_calculator.rb
@@ -1,6 +1,6 @@
 class RelatedTagCalculator
   def self.find_tags(tag, limit)
-    Post.tag_match(tag).limit(limit).select("posts.tag_string").order("posts.md5").map(&:tag_string)
+    Post.tag_match(tag).limit(limit).select("posts.tag_string").reorder("posts.md5").map(&:tag_string)
   end
   
   def self.calculate_from_sample_to_array(tags, category_constraint = nil)
diff --git a/app/models/post.rb b/app/models/post.rb
index 8ea8ca52c..1d7245a24 100644
--- a/app/models/post.rb
+++ b/app/models/post.rb
@@ -661,7 +661,7 @@ class Post < ActiveRecord::Base
       relation = add_range_relation(q[:height], "posts.image_height", relation)
       relation = add_range_relation(q[:score], "posts.score", relation)
       relation = add_range_relation(q[:filesize], "posts.file_size", relation)
-      relation = add_range_relation(q[:date], "posts.created_at::date", relation)
+      relation = add_range_relation(q[:date], "date(posts.created_at)", relation)
       relation = add_range_relation(q[:general_tag_count], "posts.tag_count_general", relation)
       relation = add_range_relation(q[:artist_tag_count], "posts.tag_count_artist", relation)
       relation = add_range_relation(q[:copyright_tag_count], "posts.tag_count_copyright", relation)
diff --git a/app/presenters/post_set_presenter.rb b/app/presenters/post_set_presenter.rb
deleted file mode 100644
index 754be1c34..000000000
--- a/app/presenters/post_set_presenter.rb
+++ /dev/null
@@ -1,32 +0,0 @@
-class PostSetPresenter < Presenter
-  attr_accessor :post_set, :tag_set_presenter
-  
-  def initialize(post_set)
-    @post_set = post_set
-    @tag_set_presenter = TagSetPresenter.new(RelatedTagCalculator.calculate_from_sample_to_array(@post_set.tag_string).map {|x| x[0]})
-  end
-  
-  def posts
-    post_set.posts
-  end
-  
-  def tag_list_html(template)
-    tag_set_presenter.tag_list_html(template)
-  end
-  
-  def post_previews_html(template)
-    html = "<div class='post-previews'>"
-    
-    if posts.empty?
-      return template.render("post_sets/blank")
-    end
-    
-    posts.each do |post|
-      html << PostPresenter.preview(post)
-    end
-    
-    html << '</div>'
-    
-    html.html_safe
-  end
-end
diff --git a/app/presenters/post_set_presenters/post.rb b/app/presenters/post_set_presenters/post.rb
index 1a5b0351c..1b47a0594 100644
--- a/app/presenters/post_set_presenters/post.rb
+++ b/app/presenters/post_set_presenters/post.rb
@@ -10,14 +10,38 @@ module PostSetPresenters
     
     def related_tags
       if post_set.is_single_tag?
-        tag = Tag.find_by_name(post_set.tag_string)
-        if tag
-          return tag.related_tag_array.map(&:first)
-        end
+        related_tags_for_single
+      elsif post_set.is_empty_tag?
+        popular_tags
+      else
+        related_tags_for_group
+      end
+    end
+    
+    def popular_tags
+      n = 1
+      results = []
+      
+      while results.empty? && n < 256
+        query = n.days.ago.strftime("date:>%Y-%m-%d")
+        results = RelatedTagCalculator.calculate_from_sample_to_array(query).map(&:first)
+        n *= 2
       end
       
+      results
+    end
+    
+    def related_tags_for_group
       RelatedTagCalculator.calculate_from_sample_to_array(post_set.tag_string).map(&:first)
     end
+    
+    def related_tags_for_single
+      tag = Tag.find_by_name(post_set.tag_string)
+
+      if tag
+        return tag.related_tag_array.map(&:first)
+      end
+    end
 
     def tag_list_html(template)
       tag_set_presenter.tag_list_html(template)
diff --git a/app/presenters/tag_set_presenter.rb b/app/presenters/tag_set_presenter.rb
index 92ffa0abe..31c2e3554 100644
--- a/app/presenters/tag_set_presenter.rb
+++ b/app/presenters/tag_set_presenter.rb
@@ -12,7 +12,7 @@ class TagSetPresenter < Presenter
   def tag_list_html(template, options = {})
     html = ""
     html << "<ul>"
-    @tags.flatten.each do |tag|
+    @tags.each do |tag|
       html << build_list_item(tag, template, options)
     end
     html << "</ul>"
diff --git a/db/migrate/20100204214746_create_posts.rb b/db/migrate/20100204214746_create_posts.rb
index 6ad6c8cd4..dbac9890c 100644
--- a/db/migrate/20100204214746_create_posts.rb
+++ b/db/migrate/20100204214746_create_posts.rb
@@ -68,6 +68,7 @@ class CreatePosts < ActiveRecord::Migration
     add_index :posts, :uploader_id
     add_index :posts, :uploader_ip_addr
     
+    execute "create index index_posts_on_created_at_date on posts (date(created_at))"
     execute "CREATE INDEX index_posts_on_mpixels ON posts (((image_width * image_height)::numeric / 1000000.0))"
 
     execute "SET statement_timeout = 0"
diff --git a/script/upgrade_schema.sql b/script/upgrade_schema.sql
index 7f3751172..3dc30406f 100755
--- a/script/upgrade_schema.sql
+++ b/script/upgrade_schema.sql
@@ -3049,7 +3049,7 @@ create index index_posts_on_uploader_ip_addr on posts (uploader_ip_addr);
 drop function trg_posts_tags__delete();
 drop function trg_posts_tags__insert();
 update posts set uploader_id = 1 where uploader_id is null;
-
+create index index_posts_on_created_at_date on posts (date(created_at));
 alter table post_appeals rename column user_id to creator_id;
 alter index index_post_appeals_on_user_id rename to index_post_appeals_on_creator_id;
 alter table post_appeals rename column ip_addr to creator_ip_addr;