This article has a lot of well-sourced information, but to sum up:

1.  The Jones Act has not acted as a barrier for any foreign ships being used in the Gulf cleanup.  Although the Jones Act is not currently applicable, the administration has taken steps to expedite a waiver should the need arise.

2.  Some of the wingnuts have cited the State Department's announcement of the acceptance of foreign assistance to falsely suggest that it took 70 days to accept foreign assistance.  ""In fact, before today, there were 24 foreign vessels operating in the region and nine countries had provided boom, skimmers and other assistance. As early as May 11th boom arrived from Mexico, Norway and Brazil."

3.  The number of offers of foreign "assistance" varies depending on how you define such offers.  Many offers of "assistance" are really offers from either private organizations or governments to sell equipment or services, which may or may not meet the needs of the Unified Command, or may/may not meet safety guidelines.  As Adm. Thallen indicated in his July 2 news conference:

107 offers of foreign assistance from 44 countries and four international organizations. Sixty-eight of those offers were really government-to-government -- this one government extending the offer of equipment or personnel or supplies to us. Thirty-nine of those offers were by private offers, which become another potential source of supply for the types of equipment we might need... Out of the 68, government-to-government offers to date 35 appear to be equipment or resources that we could use.  We've accepted nine of those offers already and 24 of those offers are being processed right now through the State Department for acceptance...Of the 39 private offers, it looks like 30 of those are equipment or types of materials that we could use.  Those have been provided to our folks that are out there acquiring whatever it is booms, dispersants, or skinny material and they become part of the broader source of supply that we're pursuing in trying to resource our operation moving forward.

There isn't much information available as to why specific offers were turned down, but on June 22 the UC responded:

Those offers of international assistance that were not accepted, while greatly appreciated, did not meet the operational requirements of the Unified Command. These offers have not been declined because they may be needed in the future as response strategies change. Some challenges in accepting these offers included:

    * Equipment failed to meet US requirements/specifications (i.e. dispersant not on approved list/containment boom made of non-approved material)
    * Contingencies placed on the offers proved logistically impracticable when compared to other sources.
    * In one instance, the offering country's export laws prohibited delivery of the assistance
    * Contingencies placed on the offers made it difficult for the Unified Command to meet the contingency

Precisely why Jimakappj made allusions to rejected foreign aid, without mentioning specifics.  When he does get into specifics, he doesn't get those correct.  For example, he appears to be claiming that Obama blocked an unnamed ship "for over 2 months."  He follows up with specifics about Dutch skimmer technology, without indicating if this is the "ship" he was referring to earlier.  The truth is,:

Three days after the accident, the Dutch government offered advanced skimming equipment capable of sucking up oiled water, separating out most of the oil, and returning the cleaner water to the Gulf. But citing discharge regulations that demand that 99.9985 percent of the returned water is oil-free, the EPA initially turned down the offer. A month into the crisis, the EPA backed off those regulations, and the Dutch equipment was airlifted to the Gulf

Louisiana Gov. Bobby Jindal has spent the past week and half fighting to get working barges to begin vacuuming crude oil out of his state's oil-soaked waters. By Thursday morning, against the governor's wishes, those barges still were sitting idle, even as more oil flowed toward the Louisiana shore.

Sixteen barges sat stationary Thursday, although they had been sucking up thousands of gallons of BP's oil as recently as Tuesday.

The Coast Guard came and shut them down," Jindal said. "You got men on the barges in the oil, and they have been told by the Coast Guard, 'Cease and desist. Stop sucking up that oil.'"

A Coast Guard representative told ABC News that it shares the same goal as the governor.

"We are all in this together. The enemy is the oil," said Coast Guard Lt. Cmdr. Dan Lauer.

But the Coast Guard ordered the stoppage because of reasons that Jindal found frustrating. The Coast Guard needed to confirm that there were fire extinguishers and life vests on board, and then it had trouble contacting the people who built the barges.

From that wingnut ABC News. (Sarcasm alert)

Evidently the Coast Guard, in this case, can't inspect while the barges work.

I wonder if they can chew bubble gum and walk.

Bureaucratic bumbling while the oil pours.

Yet Obama never said a word.

He is not, has not been and never will be concerned about this. It is claimed he is a narcissist. That everything must be about him.