online tools

Web has progressed so much that some people have coined buzzwords like Web2.0 .I will explain some tools which i found interesting
Blogs.
blogger, wordpress ..
If you are reading this, you already know this. If you dont have one, start one now!
RSS Feeds.
Dynamic content sites like news sites, blogs supports something called RSS feeds. You can subscribe to these feeds and use a feed reader to read them, just like mail. I think Joel Spolsky once remarked the difference between reading a feed and going to the site. Its like looking every second whether it is 3'o clock / setting an alarm for 3'o clock. There are many varieties of feed readers ranging from desktop clients, browser integrated to online ones.
Desktop.
RSS Bandit, Omea Reader etc.
These readers also support tabbed browsing.
Browser Based.
Firefox builtin live bookmarks, Opera, IE7 If you are using Firefox, you can get good plugins like Sage. The builtin live bookmarks are pretty primitive. Opera has a very good feed reader integrated. These tools have added advantage that if you are browsing a site having feed, a button will be shown in the address bar which you can click to subscribe. In desktop/online clients you have to manually copy paste the rss link.
Online.
Bloglines, Google Reader, Newsalloy
Advantage is that you dont have to install any client side things.
Opml
Most of the readers support something called Opml format. This represents your collection of feeds. You can import/export opml. Once you create your opml, you can experiment with various clients. (opera9 supports importing/exporting of opml). Try out some opmls from http://indibloggies.org/nominations-2005/
Bookmarking.
del.icio.us, furl, scuttle, google bookmarks, yahoo myweb2.0
These sites support saving your bookmarks online. There are many advantages like being able to access yor bookmarks from any computer, accessing others bookmarks etc. Many of them allows accessing others bookmarks as rss feeds. For eg you can access my bookmarks here. So if you have any interesting links to share, share it using these tools Posting a bookmark while browing is easy. You just need to get the bookmarklets from these sites and click on them. del.ici.ous supports firefox extension which is little more easy. Also there is another browser called Flock (built on top of firefox) which makes it very easy to add bookmarks. It also support client side caching of your bookmarks
Many of these tools (blogs, bookmarking sites etc) support something called tags. This is the category which the link belongs to. You will be able to access the popular links for that tag etc. For eg this is the link for popular links tagged with name ai in del.icio.us
Online chats.
gtalkr, meebo
Again advantage is you dont have to install any client side things. meebo supports multiple chats like yahoo, aim etc
Picture Sharing.
Flickr
Here you share your pictures. Flickr has tagging mechanism like del.icio.us
Blog Searching
Technorati, Google Blog Search, Icerocket
pretty much self explanatory
Dictionary
Answers.com, wikipedia
If you need to know about anything, just go to these sites and search. Most of the browsers support adding search plugins to these sites.
News sites
digg, slashdot, reddit
Of course i will link only technology sites :). digg is one serious contender for slashdot. You have to subscribe to the feed because it spits out tons of news items in a day.
Im not saying anything about podcasting as i dont use it now.