Colic is a very common condition amongst babies, especially boys. According to some of the websites, 1 in 4 babies is colic. If you dread the onset of evening, because you are so sure your baby is going to start crying incessantly and unexplainably, then your baby is probably colic too. Being colic does not mean your baby is unhealthy. It just means its digestive system is growing and becoming strong and stronger. As a starting point, you can read about colic at http://en.wikipedia.org/wiki/Baby_colic and dispel any fears you have.
Firstly, you must understand that till date, nobody actually knows the cause of colic! No amount of research has been able to discover that conclusively... all that researchers have figured out is that colic is not at all an adverse health condition. It is not harmful. It is nothing to be afraid of. It's merely a part of the baby's growing adventures. Hence there is no actual "remedy" for colic. Just a few things that you can do to distract and soothe the baby when it cries...
a) Our baby's paediatrician prescribed a drops called "Colicaid" to improve digestion. It helped a bit.
b) But more than medicine, what you need is patience and love, to deal with and soothe a baby that cries in a high pitched tone, incessantly, without even opening its eyes to look at any toys you might show to distract it. Be calm and believe in the fact that this is a very temporary, passing phase.
c) Rest the baby on your shoulders and pat and stroke its back such that its stomach is pressed down.
d) Try rocking the baby in a cradle, or keep it in your lap and swing steadily in a swing.
e) Try taking your baby out to the balcony or verandah and let him watch the greenery and hear the birds chirp -- nothing helps more than this! If your baby is big enough, then take him out for a stroll in the pram.
If any other solution worked best for you, do let us all know.