The DTE RS-232 module is a tight and tidy way to convert RS-232 (computer-level) signals down to a microcontroller level signal strengths. DCE means it's configured as a "Data Communications Equipment" (with 9 holes).
Basic breakout board for FTDI's popular USB to UART IC. Now with internal oscillator and EEPROM, the FT232RL is an impressive IC!
The Prop Plug is a compact USB to Serial connector for microcontroller programming and communication. We're about the best place in the universe to get them!
Add a USB drive or thumbdrive to your microcontroller!
The I2C-RTC board is a 6-pin CMOS Real-time Clock device using I2C bus. There are no external components required.