In the Name of Allah, most Compassionate, most Merciful

Riba is one of the most disgusting thing in the sight of Allah and those who die without stopping Riba transactions and repenting will be in hellfire forever!  Those who allow Riba in any form, or allow credit cards or delay payments or mortgages or interest have left the fold of Islam.  Those who deal with it have reserved a place in hellfire for the gain of a house or car or other miserable things or just to live among disbelievers.  The evidences from hadith and sunnah are as follows:

Quran 2:275-279. Those who eat Ribâ will not stand (on the Day of Resurrection) except like the standing of a person beaten by Shaitân leading him to insanity. That is because they say: "Trading is only like Ribâ," whereas Allâh has permitted trading and forbidden Ribâ. So whosoever receives an admonition from his Lord and stops eating Ribâ shall not be punished for the past; his case is for Allâh (to judge); but whoever returns, such are the dwellers of the Fire - they will abide therein forever.  Allâh will destroy Ribâ and will give increase for Sadaqât (deeds of charity, alms, etc.) And Allâh likes not the disbelievers, sinners.  O you who believe! Be afraid of Allâh and give up what remains from Ribâ, if you are believers.  And if you do not do it, then take a notice of war from Allâh and His Messenger but if you repent, you shall have your capital sums. Deal not unjustly (by asking more than your capital sums), and you shall not be dealt with unjustly.

Receiving and giving Riba both are prohibited as evident from Quran and following hadith.

Sahih Al-Bukhari Hadith 7.259 Narrated by Abu Juhaifa
The Prophet cursed the lady who practices tattooing and the one who gets herself tattooed, and one who eats Riba' and the one who gives it. And he prohibited taking the price of a dog, and the money earned by prostitution, and cursed the makers of pictures.  

There are many punishments for dealing with Riba in this world and the worst in hereafter.

Sahih Al-Bukhari Hadith 3.298 Narrated by Samura bin Jundab
The Prophet said, "This night I dreamt that two men came and took me to a Holy land whence we proceeded on till we reached a river of blood, where a man was standing, and on its bank was standing another man with stones in his hands. The man in the middle of the river tried to come out, but the other threw a stone in his mouth and forced him to go back to his original place. So, whenever he tried to come out, the other man would throw a stone in his mouth and force him to go back to his former place." I asked, "Who is this? "I was told, '"The person in the river was a Riba-eater."

Riba comes in many shapes and sizes, but all the same things and believers must be careful in their lives so not to introduce Riba.

Sahih Al-Bukhari Hadith 3.506 Narrated by Abu Said al Khudri
Once Bilal brought Barni (i.e. a kind of dates) to the Prophet and the Prophet asked him, "From where have you brought these?" Bilal replied, "I had some inferior type of dates and exchanged two Sas of it for one Sa of Barni dates in order to give it to the Prophet to eat." Thereupon the Prophet said, "Beware! Beware! This is definitely Riba (usury)! This is definitely Riba (Usury)! Don't do so, but if you want to buy (a superior kind of dates) sell the inferior dates for money and then buy the superior kind of dates with that money."

Sahih Al-Bukhari Hadith 3.386 Narrated by Abu Salih Az Zaiyat
I heard Abu Said Al-Khudri saying, "The selling of a Dinar for a Dinar, and a Dirham for a Dirham (is permissible)." I said to him, "Ibn 'Abbas does not say the same." Abu Said replied, "I asked Ibn 'Abbas whether he had heard it from the Prophet or seen it in the Holy Book. Ibn 'Abbas replied, "I do not claim that, and you know Allah's Apostle better than I, but Usama informed me that the Prophet had said, 'There is no Riba (in money exchange) except when it is not done from hand to hand (i.e. when there is delay in payment).' "

I would like to point out that the so called Islamic banks are eating Riba as well by imitating the Riba banks but calling it with different system or names!  They are doing Riba also because of above hadith that they are not dealing hand-to-hand and with same amounts!

Sahih Al-Bukhari Hadith 3.379 Narrated by Ibn Umar
The Prophet said, "The selling of wheat for wheat is Riba except if it is handed from hand to hand and equal in amount. Similarly the selling of barley for barley, is Riba except if it is from hand to hand and equal in amount, and dates for dates is usury except if it is from hand to hand and equal in amount.

So Riba also goes with gold to gold or silver to silver and money to money if not done according to the above hadith.