How should I go about triggering sound effects

[JRuben]

I (obviously) play bass for my band and we have a keyboard player, but some songs require me to trigger pre recorded sound effects (such as the beginning of In The Lap of The Gods *album version* or the sequencer breaks in spirit of radio). Right now I have it loaded on my mac and trigger them through garage band with a plugged in midi keyboard. Is there some sort of foot pedal out there that can be loaded with sounds so I don't have to use my mac. Also, cheaper the better

 

[NoiseNinja]

You can both get midi foot pedals to trigger it from your Mac, or as you wish get a separate pedal that can store sound. For this use a programable looper pedal will do

I would imagine this would be perfect for your requirements:

Digitech JamMan Stereo

Digitech JamMan Looper/Phrase Sampler - stereo FX pedal. Store over 35 minutes of mono, CD-quality loops in 99 internal memories, optional SDHC card can store over 16 hours (with optional 8GB or higher SDHC memory card) of CD-quality audio in 99 additional memories (198 total), 44.1kHz sampling rate (CD quality), USB port, record rhythm loops and solo over them on the fly, aux input, reverse playback, 4x heavy-duty metal footswitches for looping and loop selection, 3x stop modes (stop, finish and fade), slow down or speed up any loop without changing pitch, balanced XLR mic input, metronome with multiple rhythm sounds and time signatures, automatic recording, includes power supply.

 

[seamonkey]

If you want to keep the Mac or use a cheap iPod touch, This will talk bluetooth to it to kick off loops

If you want to go real cheap look for USB foot switches.
$10 for a single, $30 for a triple

 

[seamonkey]

Another wireless to mac or ios
Livid Instruments