Zakat ul-Fitr

None of us can escape not saying a few misplaced words during Ramadhan. It is from the Mercy of Allah SWT that He prescribed on us Zakat al-Fitr to get rid of the bad effect of vain talks and useless speeches in Ramadhan, as well as to feed the needy on the day of `eid and make him happy on that day as well.
Zakat al-Fitr is mandatory on every Muslim on his behalf and on the behalf of all people he is in charge of.
"The Muslim gives it for himself and for those whom he takes care of-. young or old, male or female, free or slave - due to the hadeeth of Ibn 'Umar, radiyallaahu 'anhuma: "Allah's Messenger ordered Sadaqatul-Fitr on behalf of the young and the old, and the free and the slave - whom you provide for." [ad-Daraqutni and al-Baihaqui : Hasan]"(1)
Also Ibn `Umar said "Allah's Messenger, salla Allahu alaihi wa sallam, obligated Zakat al-Fitr [for Ramadan upon the people]".[Bukhari and Muslim]
Another Hadith gives more details :
Ibn 'Umar said, "The Prophet made incumbent on every male or female, free man or slave, the payment of one Saa` of dates or barley as Sadaqat-ul-Fitr (or said Sadaqa-Ramadan)." The people then substituted half Sa' of wheat for that. Ibn 'Umar used to give dates (as Sadaqat-ul-Fitr). Once there was scarcity of dates in Medina and Ibn 'Umar gave barley. 'And Ibn 'Umar used to give Sadaqat-ul-Fitr for every young and old person. He even used to give on behalf of my children. Ibn 'Umar used to give Sadaqatul-Fitr to those who had been officially appointed for its collection. People used to give Sadaqat-ul-Fitr (even) a day or two before the 'Eid. [Bukhari]
Ibn'Abbaas, radiyalloahu'anhu, that he used to say: "He who brings wheat it will be accepted from him, whoever brings barley it will be accepted from him whoever brings dates it will be accepted from him, whoever brings rye it will be accepted from him, and whoever brings raisins it will be accepted from him, and I think he said : whoever brings (barley) gruel it will be accepted from him. [Ibn Khuzaimah with a Sahih Isnad]
Zakat al-Fitr has to be given in the form of food. That is the practice of the Messenger of Allah salla Allahu alaihi wa sallam and the practice of the Sahabah. It also has to be given to the poor before Eid Prayer.
Ibn `Abbas reported that the Messenger of Allah, salla Allahu alaihi wa sallam, enjoined Zakat al-Fitr on the one who fasts to shield one's self from any indecent act or speech and for the purpose of providing food for the poor. It is accepted as zakah for the person who pays it before the `Eid Salah, and it is a mere sadaqah for one who pays it after the Salah" [Abu Dawud, an-Nasa'i and Ibn Majah : Hasan]
It can be given a day or two before Eid as well and [Shaikh Ali Hasan and Shaikh Salim al-Hilali say :] it is from the Sunnah that there should be a person with whom it is gathered just as the Prophet entrusted Abu Hurairah, radiya Allahu 'anhu, who said: "Allah's Messenger entrusted me to look after the zakah of Ramadan." [Bukhari]
Also, Ibn 'Umar, radiya Allahu 'anhu, used to give some of it to those who would collect it - and they were those whom the imam sent to collect it, and that was a day or two before `Eidul-Fitr. It is reported by Ibn Khuzaimah by way of 'Abdul-Waarith from Ayyoob: I said: "When did Ibn 'Umar used to give the saa'?" He said: "When the collectors had finished." I said: "When did the collectors finish?" He said: "A day or two days before the day of Fitr."
As for its wisdom, "It has been prescribed by the Wise Legislator as a purification for those who fasted, from loose and indecent talk, and to feed the poor Muslims so that they have enough provision for that day - as is shown by the previous hadeeth of Ibn 'Abbaas, radiya Allahu 'anhuma."
(1) From the book "Fasting in Ramadan as observed by the Prophet salla Allahu alaihi wa sallam" by Shaikh Ali Hasan and Shaikh Salim al-Hilali