Handy Sites for building Websites

Name availability & Launching:
List of sites to submit to
Name Check

User Feedback:
User Voice
Snap engage
#User Tracking
Olark
Refining your Design

Crowd Sourced User Feedback:
FiveSecondTest
Feedback Army
Concept Feedback
PickFu - Ask is A better than B ?

Is my Server up?
Pingdom  - pings you over HTTP
Blame Stella - good for server side computation time
Monitor us - pings you over HTTP

Page Speed:
Y Slow - The Classic!
Simulate huge concurrent load on your server

Metrics:
Kiss Metrics
Live Metrics - GoSquared
datadog - (server status too)

Stress Test:
Gatling
Siege

AB Testing:
Visual Website Optimizer

Building Mobile sites:
Sencha

Mocking:
Mocking Bird
Balsamiq

Launch Pages:
Launcheffectapp
My Beta List
UnBounce

Accounts:
Quickbooksonline
Xero

Payments:
braintreepayments


Cools JS widgits:
Fast JS test & dev
Slidedown notifications
Example of CSS3 rollovers
Twitter Bootstrap - HTML, CSS & JS components
Twitter Bootstrap Extensions
Better Twitter Bootstrap notifications
Pretty Selects and menus
Form Validation made easy
Data Visualizatino D3js 
wrapbootstrap - take bootstrap make prettier

Social Plugins
The widget with all social sites

Design Resources:
Crowd Spring
99 Designs

Graphics & Icons:
Fam Fam Fam - Free icons
Paid Icons and More Icons
Completely Free clipart
Social Buttons (FB & twitter)
More Icons
Font Awesome

CRM / Marketing :
Office Autopilot
Infusion Soft
Intercom/
Custora

Marketting Emails:
Mailchimp vs Campaign Monitor

Transactional Emails
MailGun - Email only
AWS email
Postmark
Sendgrid
Mandrill (from Mailchimp)

Deals:
http://www.startuppack.org/

And finally the best site for getting random small things done
Fiverr