After Hours Trading - Pre-Market Trading
CNN AH After Hours: 24 Hour Stock Market and Forex Data from CNNMoney.com
CNN PM Pre-Market: Stock Trading Before the Markets Open from CNNMoney.com
TD AH TradingDay.com - After Hours Trading - Pre-Market Trading
NASDAQ AH After Hours Trading | Afterhours Stock Market Quotes - NASDAQ.com
NASDAQ PM Pre-Market Trading | Premarket Stock Quotes - NASDAQ.com

Short Position/Influence
Short Interest Data: Short Interest Stock Short Selling Data, Shorts, Stocks: Short Squeeze
SEC new rules on short selling Regulation SHO Threshold Security List
Shortable Stocks: IB Contract Information Center

Technical Scanning
Stockcharts Stock Scan: Predefined Scans:
Profitspi Screener Help - Technical Analysis criteria
Yahoo Stock Screener - Yahoo! Finance
Stockta Stock Technical Analysis
Dojispace Stock Scan - Stock Screen - Stock Screener - Stock Scanning - Candlestick Scan, MACD Scan, Stochastic Scan, Moving Average Scan, RSI Scan

Fundamental Scanning
Large Caps Screener Help - Fundamental criteria
Small Caps Quotes and Research

Charting
Profitspi Stock Charts, Portfolio Tracking and Stock Screening
Bigcharts BigCharts: Stock Charts, Screeners, Interactive Charting and Research Tools
Stockconsultant StockConsultant.com - Technical Analysis of Stocks with stock quotes, charts, searches, screens, news and analysis of the market.
Stockcharts StockCharts.com - Simply the Web's Best Stock Charts
Google Google Finance
Wikinvest Investing Wiki with Research about Companies, Investment Concepts, and more...
yahoo Yahoo! Finance

Level II
Level II Quotes

Calculators
Stock Hideout - Calculators