DropBoks – Store files Online
If you are looking for a service where you can upload/download files without any other features try DropBoks. It is a single page application which makes use of Ajaxian Prototype. You can store upto 1GB of data. The UI is clean, No bells, no whistles, easy signup with very simple navigation and is ad free. But individual files cant be larger than 50MB, and only one file can be downloaded at a time.
Worth trying it out and Im damn sure you will definitely love it.
Web Brush - Active Colloboration tool
Web Brush is an online multiuser web application which can be used for the creating/discussing diagrams, flowcharts, schemas etc., Using WebBrush you can share diagrams/texts/images with your friends. It has a chat panel for sending text messages. WebBrush can be very well used for educational purposes.
The UI is awe inspiring with clean use of Ajax and Javascripts.
BTW it doesnt work with Firefox and I was forced to use IE5.5+ 
Zoho Chat – Web based Chat
Zoho Chat is an online web based instant messaging service. It doesnt require any download/installation and is 100% free. With Zoho Chat you can very well perform Group Chat, archive the conversations for future reference and even share the conversation with other members.
There are many other web based chat services available. Some of them include Meebo, ILoveIM, Mabber, eMessenger, MessengerFX, Wablet, Goowy, Imunitive, RadiusIM, Vicito, KoolIM(I blogged abt this here)
BTW Zoho offers many other services as well. Do check it here.
