Update 12/29/11: A new recent comments gadget with avatars is installed on the blog, you might consider using it instead of this gadget.
Blogger Gadget directory has two recent comments gadgets, Top Comments by Ziyush and Recent Comments by Blogger Buster, but both suffer from same problems.
Bug: the anchor of the link to the comment is broken. It should be ...showComment=COMMENTID#COMMENTANCHOR but it is ...showComment=COMMENTID#comment-COMMENTANCHOR. When you have many comments, it would be really nice if the link took you to the right comment, not to the top of the page.
Bug: sometimes gadget does not show anything, sometimes load times are long. Annoying.
Bug/feature: Strings cannot be translated. I don't want in my Finnish blog to have texts "wrote..." and "Continue >>", but "kirjoitti:" and "Lue lisää >>" instead.
Bug/cosmetic: styles don't look good, not the same as in blog (for example all links are underlined).
Missing features: CSS cannot be modified. Post titles cannot be used. Customization very limited.
Missing feature: Always gets x number of chronologically latest comments, but what if you wanted the latest comments all from different posts, or if you wanted maximum of 2, or 3, comments per same post, to prevent one topic from "flooding" the recent comments?
Own gadget to the resque
Because of all this, I first used RSS feed gadget for displaying recent comments, until yesterday, when I started developing something better. My goal was to make a gadget, which has working link anchors, customizable CSS styles and allow translating the strings and allow other modifications, too.
Along the way I added the possibility to limit comments count per post to 1...[number of recent comments shown], and that is actually really great. You can also choose not to limit, when the 5 recent comments are fetched regardless of their posts. And, because I think no one had done it before in a javascript gadget, I also fetched the post titles for the comments :) Although I only use those in link titles (shown when user hovers over the link), but you can edit the code and show it in the link, for example, like "Gary commented on We're back in business!...".
Load times are way better and no "blank recent comments" have been detected with my gadged.
To use it, add HTML/Javascript gadget to your blog, and paste following code into it:
This gadget is installed in this blog, too. In the gadget there are some easily configurable things, and of course you can change anything in the code, if you can...
You can configure CSS styles, number of recent comments (numRecentComments), length of comment excerpt (numCommentChars), maximum comments per post (numPerPost), texts (txtWrote and txtMore), and whether to load titles or not (getTitles; not loading them makes the gadget run yet a tiny bit faster).
If you want to customize the code, you can, but I hope you know your way around and can do it on your own.
Hope you like it! I do, but now I just cannot make up my mind, whether to set numPerPost to 1 or 2, with 5 recent comments... both good choices... Which would you use?
Update 11/02/11: This hack is no longer installed in this blog. I developed it further. I will post the new Recent comments in a while, stay tuned.
Update 11/03/11: A new gadget with avatars is installed on the blog.
Update 12/29/11: A new gadget with avatars (fetched differently) is installed on the blog.
Update Jan 2nd 2012: Deleted comments (This post has been removed by the author.) no longer have "alternate" link in comment feeds, like they used to, which can cause the recent comments to disappear. I modified the script to prevent this: line 69 is modified and line 76 is new.